subject:"\[music\-dsp\] Dither video and articles"

I've read that the Pono DAC is Sabre 9018.

E

On Tue, Feb 10, 2015 at 2:27 PM, Zhiguang Zhang  wrote:

> Actually scratch that 2nd thought.  It would be good to know what DAC the
> Pono device contains.
>
> -EZ
>
> On Tue, Feb 10, 2015 at 5:20 PM, Zhiguang Zhang 
> wrote:
>
> > Re:Pono, what about the DAC in the device?  That could make an audible
> and real difference.  Also, there is undeniably more information in high
> res downloads, if the original master was recorded to tape or to hi-res in
> Pro Tools.  So, has anyone ever considered the sample-level ‘phase’ effect
> of listening to properly mastered hi-res audio if the playback chain is of
> a quality that diminishes intermodulation artifacts?
> > -EZ
> > On Tue, Feb 10, 2015 at 4:45 PM, Ethan Duni 
> wrote:
> >> I like the trend of releasing remastered material, where there is scope
> for
> >> improved quality. Which isn't always, but there's an entire generation
> of
> >> albums that were victims of the loudness wars, and various early work by
> >> artists that hadn't access to quality mastering at the time, and so on,
> >> that can benefit. This has been happening totally independent of Pono.
> >> I don't like the Pono music scam because it confounds that (legitimate)
> >> aspect with the snake oil about 24 bits and high sampling rates - while
> >> charging a premium. There is zero meaningful test results that back
> Pono's
> >> quality claims (and note how frequently their marketing adds caveats
> about
> >> comparing to "low-res MP3s," as if it's 1998 or something). And while
> there
> >> isn't a definitive formal test showing that Pono sucks, there are
> multiple
> >> informal tests without obvious methodological flaws which show that
> Pono is
> >> inferior to your regular iTunes downloads. Neil Young says he's going to
> >> give you better quality (for 2-3 times the price), and instead delivers
> >> *lower* quality (or, maybe, the same, at best).
> >> The fact that their own marketing material can't even seem to keep their
> >> story straight regarding what the high resolution is or is not supposed
> to
> >> provide you, seems to me to go to the point that this is all a marketing
> >> exercise in bullshitting the consumer with a bunch of ill-founded
> claims.
> >> For that matter, Pono's implication that one can't get improved masters
> via
> >> other routes is itself deceptive.
> >> I'm also somewhat bemused by Neil Young being the poster boy for this
> >> high-resolution snake oil. While I admittedly haven't listened to his
> >> entire catalogue, his whole style features low dynamic range,
> non-extreme
> >> spectrum, and quite high noise floors (typically easily audible at even
> >> moderate volume). Which is fine, nothing wrong with the crunchy/vintage
> >> rock sound. It just doesn't fit with the whole "we need to be able to
> hear
> >> stuff at 35kHz and -130dB" delusions.
> >> That said, this statement seems problematic:
> >>>Whether the higher resolution actually degrades the quality is a topic
> up
> >> for future debate.
> >> I mean, if you personally don't want to debate it right here and now
> that's
> >> fine. But nobody is obliged to set this stuff aside. It's immediately
> >> topical, and the test files for evaluating it have been provided in the
> >> xiph link.
> >> E
> >> On Tue, Feb 10, 2015 at 1:25 PM, Tom Duffy  wrote:
> >>> So you like the bar being raised, but not the way that Neil Young has
> >>> attempted?
> >>>
> >>> Whether the higher resolution actually degrades the quality is a
> >>> topic up for future debate.
> >>>
> >>> From the ponomusic webpage:
> >>> "...and now, with the PonoPlayer, you can finally feel the master in
> all
> >>> its glory, in its native resolution, CD quality or higher, the way the
> >>> artist made it, exactly"
> >>>
> >>> Even they are not saying it has to be higher than CD quality, just
> >>> that it has to have been made well in the first place.
> >>>
> >>> I don't get why so many people are trying to paint this as
> >>> a snake oil pitch.
> >>>
> >>> ---
> >>> Tom.
> >>>
> >>>
> >>> On 2/10/2015 1:13 PM, Ethan Duni wrote:
> >>> I'm all for releasing stuff from improved masters. There's a trend in
> my
> >>> favorite genre (heavy metal) to rerelease a lot of classics in "full
> >>> dynamic range" editions lately. While I'm not sure that all of these
> >>> releases really sound much better (how much dynamic range was there in
> an
> >>> underground death metal recording from 1991 anyway?) I like the trend.
> >>> These are regular CD releases, no weird formats (demonstrating that
> such is
> >>> not required to sell the improved master releases).
> >>>
> >>> But the thing is that you often *can* hear the extra sampling
> frequency -
> >>> in the form of additional distortion. It sounds, if anything, *worse*
> than
> >>> a release with an appropriate sample rate! Trying to sell people on
> better
> >>> audio, and then giving them a bunch of additional intermodulation
> >>> distortion is

Re: [music-dsp] Dither video and articles

2015-02-10 Thread Zhiguang Zhang

Actually scratch that 2nd thought.  It would be good to know what DAC the Pono 
device contains.

-EZ

On Tue, Feb 10, 2015 at 5:20 PM, Zhiguang Zhang 
wrote:

> Re:Pono, what about the DAC in the device?  That could make an audible and 
> real difference.  Also, there is undeniably more information in high res 
> downloads, if the original master was recorded to tape or to hi-res in Pro 
> Tools.  So, has anyone ever considered the sample-level ‘phase’ effect of 
> listening to properly mastered hi-res audio if the playback chain is of a 
> quality that diminishes intermodulation artifacts?
> -EZ
> On Tue, Feb 10, 2015 at 4:45 PM, Ethan Duni  wrote:
>> I like the trend of releasing remastered material, where there is scope for
>> improved quality. Which isn't always, but there's an entire generation of
>> albums that were victims of the loudness wars, and various early work by
>> artists that hadn't access to quality mastering at the time, and so on,
>> that can benefit. This has been happening totally independent of Pono.
>> I don't like the Pono music scam because it confounds that (legitimate)
>> aspect with the snake oil about 24 bits and high sampling rates - while
>> charging a premium. There is zero meaningful test results that back Pono's
>> quality claims (and note how frequently their marketing adds caveats about
>> comparing to "low-res MP3s," as if it's 1998 or something). And while there
>> isn't a definitive formal test showing that Pono sucks, there are multiple
>> informal tests without obvious methodological flaws which show that Pono is
>> inferior to your regular iTunes downloads. Neil Young says he's going to
>> give you better quality (for 2-3 times the price), and instead delivers
>> *lower* quality (or, maybe, the same, at best).
>> The fact that their own marketing material can't even seem to keep their
>> story straight regarding what the high resolution is or is not supposed to
>> provide you, seems to me to go to the point that this is all a marketing
>> exercise in bullshitting the consumer with a bunch of ill-founded claims.
>> For that matter, Pono's implication that one can't get improved masters via
>> other routes is itself deceptive.
>> I'm also somewhat bemused by Neil Young being the poster boy for this
>> high-resolution snake oil. While I admittedly haven't listened to his
>> entire catalogue, his whole style features low dynamic range, non-extreme
>> spectrum, and quite high noise floors (typically easily audible at even
>> moderate volume). Which is fine, nothing wrong with the crunchy/vintage
>> rock sound. It just doesn't fit with the whole "we need to be able to hear
>> stuff at 35kHz and -130dB" delusions.
>> That said, this statement seems problematic:
>>>Whether the higher resolution actually degrades the quality is a topic up
>> for future debate.
>> I mean, if you personally don't want to debate it right here and now that's
>> fine. But nobody is obliged to set this stuff aside. It's immediately
>> topical, and the test files for evaluating it have been provided in the
>> xiph link.
>> E
>> On Tue, Feb 10, 2015 at 1:25 PM, Tom Duffy  wrote:
>>> So you like the bar being raised, but not the way that Neil Young has
>>> attempted?
>>>
>>> Whether the higher resolution actually degrades the quality is a
>>> topic up for future debate.
>>>
>>> From the ponomusic webpage:
>>> "...and now, with the PonoPlayer, you can finally feel the master in all
>>> its glory, in its native resolution, CD quality or higher, the way the
>>> artist made it, exactly"
>>>
>>> Even they are not saying it has to be higher than CD quality, just
>>> that it has to have been made well in the first place.
>>>
>>> I don't get why so many people are trying to paint this as
>>> a snake oil pitch.
>>>
>>> ---
>>> Tom.
>>>
>>>
>>> On 2/10/2015 1:13 PM, Ethan Duni wrote:
>>> I'm all for releasing stuff from improved masters. There's a trend in my
>>> favorite genre (heavy metal) to rerelease a lot of classics in "full
>>> dynamic range" editions lately. While I'm not sure that all of these
>>> releases really sound much better (how much dynamic range was there in an
>>> underground death metal recording from 1991 anyway?) I like the trend.
>>> These are regular CD releases, no weird formats (demonstrating that such is
>>> not required to sell the improved master releases).
>>>
>>> But the thing is that you often *can* hear the extra sampling frequency -
>>> in the form of additional distortion. It sounds, if anything, *worse* than
>>> a release with an appropriate sample rate! Trying to sell people on better
>>> audio, and then giving them a bunch of additional intermodulation
>>> distortion is not a justified marketing ploy, it's outright deceptive and
>>> abusive. This is working from the assumption that your customers are
>>> idiots, and that you should exploit that to make money, irrespective of
>>> whether audio quality is harmed or not. The fact the Neil Young is himself
>>> one of the su

Re: [music-dsp] Dither video and articles

2015-02-10 Thread Zhiguang Zhang

Re:Pono, what about the DAC in the device?  That could make an audible and real 
difference.  Also, there is undeniably more information in high res downloads, 
if the original master was recorded to tape or to hi-res in Pro Tools.  So, has 
anyone ever considered the sample-level ‘phase’ effect of listening to properly 
mastered hi-res audio if the playback chain is of a quality that diminishes 
intermodulation artifacts?




-EZ

On Tue, Feb 10, 2015 at 4:45 PM, Ethan Duni  wrote:

> I like the trend of releasing remastered material, where there is scope for
> improved quality. Which isn't always, but there's an entire generation of
> albums that were victims of the loudness wars, and various early work by
> artists that hadn't access to quality mastering at the time, and so on,
> that can benefit. This has been happening totally independent of Pono.
> I don't like the Pono music scam because it confounds that (legitimate)
> aspect with the snake oil about 24 bits and high sampling rates - while
> charging a premium. There is zero meaningful test results that back Pono's
> quality claims (and note how frequently their marketing adds caveats about
> comparing to "low-res MP3s," as if it's 1998 or something). And while there
> isn't a definitive formal test showing that Pono sucks, there are multiple
> informal tests without obvious methodological flaws which show that Pono is
> inferior to your regular iTunes downloads. Neil Young says he's going to
> give you better quality (for 2-3 times the price), and instead delivers
> *lower* quality (or, maybe, the same, at best).
> The fact that their own marketing material can't even seem to keep their
> story straight regarding what the high resolution is or is not supposed to
> provide you, seems to me to go to the point that this is all a marketing
> exercise in bullshitting the consumer with a bunch of ill-founded claims.
> For that matter, Pono's implication that one can't get improved masters via
> other routes is itself deceptive.
> I'm also somewhat bemused by Neil Young being the poster boy for this
> high-resolution snake oil. While I admittedly haven't listened to his
> entire catalogue, his whole style features low dynamic range, non-extreme
> spectrum, and quite high noise floors (typically easily audible at even
> moderate volume). Which is fine, nothing wrong with the crunchy/vintage
> rock sound. It just doesn't fit with the whole "we need to be able to hear
> stuff at 35kHz and -130dB" delusions.
> That said, this statement seems problematic:
>>Whether the higher resolution actually degrades the quality is a topic up
> for future debate.
> I mean, if you personally don't want to debate it right here and now that's
> fine. But nobody is obliged to set this stuff aside. It's immediately
> topical, and the test files for evaluating it have been provided in the
> xiph link.
> E
> On Tue, Feb 10, 2015 at 1:25 PM, Tom Duffy  wrote:
>> So you like the bar being raised, but not the way that Neil Young has
>> attempted?
>>
>> Whether the higher resolution actually degrades the quality is a
>> topic up for future debate.
>>
>> From the ponomusic webpage:
>> "...and now, with the PonoPlayer, you can finally feel the master in all
>> its glory, in its native resolution, CD quality or higher, the way the
>> artist made it, exactly"
>>
>> Even they are not saying it has to be higher than CD quality, just
>> that it has to have been made well in the first place.
>>
>> I don't get why so many people are trying to paint this as
>> a snake oil pitch.
>>
>> ---
>> Tom.
>>
>>
>> On 2/10/2015 1:13 PM, Ethan Duni wrote:
>> I'm all for releasing stuff from improved masters. There's a trend in my
>> favorite genre (heavy metal) to rerelease a lot of classics in "full
>> dynamic range" editions lately. While I'm not sure that all of these
>> releases really sound much better (how much dynamic range was there in an
>> underground death metal recording from 1991 anyway?) I like the trend.
>> These are regular CD releases, no weird formats (demonstrating that such is
>> not required to sell the improved master releases).
>>
>> But the thing is that you often *can* hear the extra sampling frequency -
>> in the form of additional distortion. It sounds, if anything, *worse* than
>> a release with an appropriate sample rate! Trying to sell people on better
>> audio, and then giving them a bunch of additional intermodulation
>> distortion is not a justified marketing ploy, it's outright deceptive and
>> abusive. This is working from the assumption that your customers are
>> idiots, and that you should exploit that to make money, irrespective of
>> whether audio quality is harmed or not. The fact the Neil Young is himself
>> one of the suckers renders this less objectionable, but only slightly.
>> Anyway Pono is already a byword for "audiophile snake oil" so hopefully the
>> damage will mostly be limited to the bank accounts of Mr. Young and his
>> various financial backers in th

Re: [music-dsp] Dither video and articles

How do the crest factors of these different "sawtooth" waveforms compare?
I'd expect one with randomized phase to have a much lower crest factor.
Which is to say that I'd expect the in-phase sawtooth to activate a lot
more nonlinearity in the playback chain, which explains why that one is
easy to pick out but the various randomized ones all sound similar. It also
implies that we'd need a very fancy playback system with excellent
linearity to draw any conclusions about the underlying audibility of the
sawtooth partial phases as such.

E

On Tue, Feb 10, 2015 at 1:52 PM, gwenhwyfaer  wrote:

> On 10/02/2015, Didier Dambrin  wrote:
> > Pretty easy to check the obvious difference between a pure low sawtooth,
> and
> >
> > the same sawtooth with all partials starting at random phases.
>
> Ah, this again? Good times. I remember playing. I made 7 sawtooth
> waves with random (static) phases and one straightforward sawtooth
> wave, with all partials in phase. I just listened to it again, to
> check my memory. On a half-decent pair of headphones, the difference
> between the all-partials-in-phase sawtooth and the random-phase ones
> is readily audible, but it was rather harder to tell the difference
> between the various random-phase waves; they all kind of sounded
> pulse-wavey. On a pair of speakers through the same amp and soundcard,
> though, I can still *jst about* pick out the in-phase sawtooth -
> but I couldn't confidently tell the difference between the 7 other
> waves. Which I'm guessing has something to do with the difference
> between the fairly one-dimensional travel of sound from headphone to
> ear, vs the bouncing-in-from-all-kinds-of-directions speaker->ear
> journey.
>
> I'm only a data point, though, so I'm not brave enough to actually
> conclude anything. At least, not any more. ;)
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews,
> dsp links
> http://music.columbia.edu/cmc/music-dsp
> http://music.columbia.edu/mailman/listinfo/music-dsp
>
--
dupswapdrop -- the music-dsp mailing list and website:
subscription info, FAQ, source code archive, list archive, book reviews, dsp 
links
http://music.columbia.edu/cmc/music-dsp
http://music.columbia.edu/mailman/listinfo/music-dsp

Re: [music-dsp] Dither video and articles

2015-02-10 Thread gwenhwyfaer

On 10/02/2015, Didier Dambrin  wrote:
> Pretty easy to check the obvious difference between a pure low sawtooth, and
>
> the same sawtooth with all partials starting at random phases.

Ah, this again? Good times. I remember playing. I made 7 sawtooth
waves with random (static) phases and one straightforward sawtooth
wave, with all partials in phase. I just listened to it again, to
check my memory. On a half-decent pair of headphones, the difference
between the all-partials-in-phase sawtooth and the random-phase ones
is readily audible, but it was rather harder to tell the difference
between the various random-phase waves; they all kind of sounded
pulse-wavey. On a pair of speakers through the same amp and soundcard,
though, I can still *jst about* pick out the in-phase sawtooth -
but I couldn't confidently tell the difference between the 7 other
waves. Which I'm guessing has something to do with the difference
between the fairly one-dimensional travel of sound from headphone to
ear, vs the bouncing-in-from-all-kinds-of-directions speaker->ear
journey.

I'm only a data point, though, so I'm not brave enough to actually
conclude anything. At least, not any more. ;)
--
dupswapdrop -- the music-dsp mailing list and website:
subscription info, FAQ, source code archive, list archive, book reviews, dsp 
links
http://music.columbia.edu/cmc/music-dsp
http://music.columbia.edu/mailman/listinfo/music-dsp

Re: [music-dsp] Dither video and articles

I like the trend of releasing remastered material, where there is scope for
improved quality. Which isn't always, but there's an entire generation of
albums that were victims of the loudness wars, and various early work by
artists that hadn't access to quality mastering at the time, and so on,
that can benefit. This has been happening totally independent of Pono.

I don't like the Pono music scam because it confounds that (legitimate)
aspect with the snake oil about 24 bits and high sampling rates - while
charging a premium. There is zero meaningful test results that back Pono's
quality claims (and note how frequently their marketing adds caveats about
comparing to "low-res MP3s," as if it's 1998 or something). And while there
isn't a definitive formal test showing that Pono sucks, there are multiple
informal tests without obvious methodological flaws which show that Pono is
inferior to your regular iTunes downloads. Neil Young says he's going to
give you better quality (for 2-3 times the price), and instead delivers
*lower* quality (or, maybe, the same, at best).

The fact that their own marketing material can't even seem to keep their
story straight regarding what the high resolution is or is not supposed to
provide you, seems to me to go to the point that this is all a marketing
exercise in bullshitting the consumer with a bunch of ill-founded claims.
For that matter, Pono's implication that one can't get improved masters via
other routes is itself deceptive.

I'm also somewhat bemused by Neil Young being the poster boy for this
high-resolution snake oil. While I admittedly haven't listened to his
entire catalogue, his whole style features low dynamic range, non-extreme
spectrum, and quite high noise floors (typically easily audible at even
moderate volume). Which is fine, nothing wrong with the crunchy/vintage
rock sound. It just doesn't fit with the whole "we need to be able to hear
stuff at 35kHz and -130dB" delusions.

That said, this statement seems problematic:

>Whether the higher resolution actually degrades the quality is a topic up
for future debate.

I mean, if you personally don't want to debate it right here and now that's
fine. But nobody is obliged to set this stuff aside. It's immediately
topical, and the test files for evaluating it have been provided in the
xiph link.

E

On Tue, Feb 10, 2015 at 1:25 PM, Tom Duffy  wrote:

> So you like the bar being raised, but not the way that Neil Young has
> attempted?
>
> Whether the higher resolution actually degrades the quality is a
> topic up for future debate.
>
> From the ponomusic webpage:
> "...and now, with the PonoPlayer, you can finally feel the master in all
> its glory, in its native resolution, CD quality or higher, the way the
> artist made it, exactly"
>
> Even they are not saying it has to be higher than CD quality, just
> that it has to have been made well in the first place.
>
> I don't get why so many people are trying to paint this as
> a snake oil pitch.
>
> ---
> Tom.
>
>
> On 2/10/2015 1:13 PM, Ethan Duni wrote:
> I'm all for releasing stuff from improved masters. There's a trend in my
> favorite genre (heavy metal) to rerelease a lot of classics in "full
> dynamic range" editions lately. While I'm not sure that all of these
> releases really sound much better (how much dynamic range was there in an
> underground death metal recording from 1991 anyway?) I like the trend.
> These are regular CD releases, no weird formats (demonstrating that such is
> not required to sell the improved master releases).
>
> But the thing is that you often *can* hear the extra sampling frequency -
> in the form of additional distortion. It sounds, if anything, *worse* than
> a release with an appropriate sample rate! Trying to sell people on better
> audio, and then giving them a bunch of additional intermodulation
> distortion is not a justified marketing ploy, it's outright deceptive and
> abusive. This is working from the assumption that your customers are
> idiots, and that you should exploit that to make money, irrespective of
> whether audio quality is harmed or not. The fact the Neil Young is himself
> one of the suckers renders this less objectionable, but only slightly.
> Anyway Pono is already a byword for "audiophile snake oil" so hopefully the
> damage will mostly be limited to the bank accounts of Mr. Young and his
> various financial backers in this idiocy. Sounds like the product is a real
> dog in industrial design terms anyway (no hold button, awkward shape,
> etc.). Good riddance...
>
> E
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews,
> dsp links
> http://music.columbia.edu/cmc/music-dsp
> http://music.columbia.edu/mailman/listinfo/music-dsp
>
>
> NOTICE: This electronic mail message and its contents, including any
> attachments hereto (collectively, "this e-mail"), is hereby designated as
> "confidential and proprietary." This e-mail m

Re: [music-dsp] Dither video and articles

2015-02-10 Thread Michael Gogins

What I am interested in, regarding this discussion, is quite specific.
I make computer music using Csound, and usually using completely
synthesized sound, and so far only in stereo. Csound can run at any
sample rate, can output floating-point soundfiles, and can dither. My
sounds are not necessarily simple and cover the whole frequency range
and a wide dynamic range.

My only real question is, since the signal path right up to the point
where the soundfile is written is likely to be the same in all cases,
what kind of differences if any can I try to hear in CD audio versus
say 96 KHz floating-point?

These differences (if any) will be caused by the different Csound
sampling rate, the different soundfile sample word size/dynamic range,
and of course the different things that might happen to these two
kinds of soundfiles on their way out of a high-quality
DAC/amplifier/monitor speaker rig.

At times, my pieces have fortunately been presented in nice quiet
concert halls with really good amplifiers and speakers. I have also
been able to listen a few times in high-end recording studios designed
for this kind of music (this is a very different listening
experience).

Regards,
Mike

-
Michael Gogins
Irreducible Productions
http://michaelgogins.tumblr.com
Michael dot Gogins at gmail dot com

On Tue, Feb 10, 2015 at 4:13 PM, Ethan Duni  wrote:
> I'm all for releasing stuff from improved masters. There's a trend in my
> favorite genre (heavy metal) to rerelease a lot of classics in "full
> dynamic range" editions lately. While I'm not sure that all of these
> releases really sound much better (how much dynamic range was there in an
> underground death metal recording from 1991 anyway?) I like the trend.
> These are regular CD releases, no weird formats (demonstrating that such is
> not required to sell the improved master releases).
>
> But the thing is that you often *can* hear the extra sampling frequency -
> in the form of additional distortion. It sounds, if anything, *worse* than
> a release with an appropriate sample rate! Trying to sell people on better
> audio, and then giving them a bunch of additional intermodulation
> distortion is not a justified marketing ploy, it's outright deceptive and
> abusive. This is working from the assumption that your customers are
> idiots, and that you should exploit that to make money, irrespective of
> whether audio quality is harmed or not. The fact the Neil Young is himself
> one of the suckers renders this less objectionable, but only slightly.
> Anyway Pono is already a byword for "audiophile snake oil" so hopefully the
> damage will mostly be limited to the bank accounts of Mr. Young and his
> various financial backers in this idiocy. Sounds like the product is a real
> dog in industrial design terms anyway (no hold button, awkward shape,
> etc.). Good riddance...
>
> E
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews, dsp 
> links
> http://music.columbia.edu/cmc/music-dsp
> http://music.columbia.edu/mailman/listinfo/music-dsp
--
dupswapdrop -- the music-dsp mailing list and website:
subscription info, FAQ, source code archive, list archive, book reviews, dsp 
links
http://music.columbia.edu/cmc/music-dsp
http://music.columbia.edu/mailman/listinfo/music-dsp

Re: [music-dsp] Dither video and articles

2015-02-10 Thread Tom Duffy

So you like the bar being raised, but not the way that Neil Young has
attempted?

Whether the higher resolution actually degrades the quality is a
topic up for future debate.

From the ponomusic webpage:
"...and now, with the PonoPlayer, you can finally feel the master in all
its glory, in its native resolution, CD quality or higher, the way the
artist made it, exactly"

Even they are not saying it has to be higher than CD quality, just
that it has to have been made well in the first place.

I don't get why so many people are trying to paint this as
a snake oil pitch.

---
Tom.

On 2/10/2015 1:13 PM, Ethan Duni wrote:
I'm all for releasing stuff from improved masters. There's a trend in my
favorite genre (heavy metal) to rerelease a lot of classics in "full
dynamic range" editions lately. While I'm not sure that all of these
releases really sound much better (how much dynamic range was there in an
underground death metal recording from 1991 anyway?) I like the trend.
These are regular CD releases, no weird formats (demonstrating that such is
not required to sell the improved master releases).

But the thing is that you often *can* hear the extra sampling frequency -
in the form of additional distortion. It sounds, if anything, *worse* than
a release with an appropriate sample rate! Trying to sell people on better
audio, and then giving them a bunch of additional intermodulation
distortion is not a justified marketing ploy, it's outright deceptive and
abusive. This is working from the assumption that your customers are
idiots, and that you should exploit that to make money, irrespective of
whether audio quality is harmed or not. The fact the Neil Young is himself
one of the suckers renders this less objectionable, but only slightly.
Anyway Pono is already a byword for "audiophile snake oil" so hopefully the
damage will mostly be limited to the bank accounts of Mr. Young and his
various financial backers in this idiocy. Sounds like the product is a real
dog in industrial design terms anyway (no hold button, awkward shape,
etc.). Good riddance...

E
--
dupswapdrop -- the music-dsp mailing list and website:
subscription info, FAQ, source code archive, list archive, book reviews,
dsp links

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Re: [music-dsp] Dither video and articles

I'm all for releasing stuff from improved masters. There's a trend in my
favorite genre (heavy metal) to rerelease a lot of classics in "full
dynamic range" editions lately. While I'm not sure that all of these
releases really sound much better (how much dynamic range was there in an
underground death metal recording from 1991 anyway?) I like the trend.
These are regular CD releases, no weird formats (demonstrating that such is
not required to sell the improved master releases).

But the thing is that you often *can* hear the extra sampling frequency -
in the form of additional distortion. It sounds, if anything, *worse* than
a release with an appropriate sample rate! Trying to sell people on better
audio, and then giving them a bunch of additional intermodulation
distortion is not a justified marketing ploy, it's outright deceptive and
abusive. This is working from the assumption that your customers are
idiots, and that you should exploit that to make money, irrespective of
whether audio quality is harmed or not. The fact the Neil Young is himself
one of the suckers renders this less objectionable, but only slightly.
Anyway Pono is already a byword for "audiophile snake oil" so hopefully the
damage will mostly be limited to the bank accounts of Mr. Young and his
various financial backers in this idiocy. Sounds like the product is a real
dog in industrial design terms anyway (no hold button, awkward shape,
etc.). Good riddance...

E
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Re: [music-dsp] Dither video and articles

2015-02-10 Thread Tom Duffy


The only comment in that page that actually tells the story is buried:

--
Different media, different master

I've run across a few articles and blog posts that declare the virtues 
of 24 bit or 96/192kHz by comparing a CD to an audio DVD (or SACD) of 
the 'same' recording. This comparison is invalid; the masters are 
usually different.



The benefit end users get from Pono / Hi resolution files is exactly
this - the master was prepared without the usual requirements for
radio-play-ready compression or filtering.

Sure you can do the same in 44.1kHz/16bit or MP3 or MP4, but packaging
is everything, and it's a lot easier to market something that requires
a bigger file as being better.

Everyone gets hung up on the "but you can't hear the extra bits / extra
FS" but ignore the advantage of less GI-GO.

Tom.


On 2/10/2015 12:46 PM, Ethan Duni wrote:
why does higher-than-needed sample rate hurt audio quality?
might not be necessary, but how does it make it worse (excluding
the increased computational burden)?

The danger is that you are now including a bunch of out-of-band content in
your output signal, which can be transformed into in-band aliasing by any
nonlinearities in your playback chain. It's generally not a big deal, but
it is measurable and does hurt quality:

http://xiph.org/~xiphmont/demo/neil-young.html

This is an excellent example of the tension between audiophile
"perfectionism" (i.e., more sample rate must always be at least as good,
because digital audio is some kind of terrifying bogeyman) and actual
engineering quality control (i.e., overspec-ing systems drives up costs,
compromises the quality in other components, and generally creates more
headaches than it solves).

E


On Tue, Feb 10, 2015 at 10:54 AM, robert bristow-johnson <
r...@audioimagination.com> wrote:

On 2/10/15 1:51 PM, Ethan Duni wrote:

So to you, that Pono player isn't snake oil?

It's more the 192kHz sampling rate that renders the Pono player into snake
oil territory. The extra bits probably aren't getting you much, but the
ridiculous sampling rate can only *hurt* audio quality, while consuming
that much more battery and storage.


that's interesting.  why does higher-than-needed sample rate hurt audio
quality?  might not be necessary, but how does it make it worse (excluding
the increased computational burden)?  i always think that analog (or
continuous-time) is like having an infinite sample rate.


--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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entity.



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Re: [music-dsp] Dither video and articles

>why does higher-than-needed sample rate hurt audio quality?
>might not be necessary, but how does it make it worse (excluding
>the increased computational burden)?

The danger is that you are now including a bunch of out-of-band content in
your output signal, which can be transformed into in-band aliasing by any
nonlinearities in your playback chain. It's generally not a big deal, but
it is measurable and does hurt quality:

http://xiph.org/~xiphmont/demo/neil-young.html

This is an excellent example of the tension between audiophile
"perfectionism" (i.e., more sample rate must always be at least as good,
because digital audio is some kind of terrifying bogeyman) and actual
engineering quality control (i.e., overspec-ing systems drives up costs,
compromises the quality in other components, and generally creates more
headaches than it solves).

E


On Tue, Feb 10, 2015 at 10:54 AM, robert bristow-johnson <
r...@audioimagination.com> wrote:

> On 2/10/15 1:51 PM, Ethan Duni wrote:
>
>> So to you, that Pono player isn't snake oil?
>>>
>> It's more the 192kHz sampling rate that renders the Pono player into snake
>> oil territory. The extra bits probably aren't getting you much, but the
>> ridiculous sampling rate can only *hurt* audio quality, while consuming
>> that much more battery and storage.
>>
>
> that's interesting.  why does higher-than-needed sample rate hurt audio
> quality?  might not be necessary, but how does it make it worse (excluding
> the increased computational burden)?  i always think that analog (or
> continuous-time) is like having an infinite sample rate.
>
>
> --
>
> r b-j  r...@audioimagination.com
>
> "Imagination is more important than knowledge."
>
>
>
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews,
> dsp links
> http://music.columbia.edu/cmc/music-dsp
> http://music.columbia.edu/mailman/listinfo/music-dsp
>
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Re: [music-dsp] Dither video and articles

I'm talking about simple initial phase offsets, nothing dynamic. It's an old 
subject, you will find it back as "ghost thone" in this mailing list, with 
audio examples.


I'll redo an audio demo if you insist, but simply randomizing the *initial* 
(yes, nothing dynamic) phases of all partials of a sawtooth, will give a 
pretty distinctive metallic tone, absolutely nothing like a pure sawtooth, 
and only differing in partial phases.





-Message d'origine- 
From: robert bristow-johnson

Sent: Tuesday, February 10, 2015 7:47 PM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles

On 2/10/15 1:22 PM, Didier Dambrin wrote:
Of course, a lot of visually different waveshapes sound the same, as soon 
as the phase relationship between neighboring partials is shifted by the 
same amount.

they can be shifted by *any* amount, as long as it's static.

in fact, what do you mean by "same amount"?  same amount of time?  then
that's just a delay.

same amount of phase?  well that *does* change the waveshape, but it can
be any amount of phase for a perfectly periodic waveform.  when things
get less than perfectly periodic, then you have changing harmonic
coefficients, both in amplitude and phase.



That doesn't mean it's always the case


i agree.  if the phase changes rapidly enough, you'll hear it as a
detuned or slightly non-harmonic partial.

i can't argue Andrew Horner's case for him (he just didn't think he
needed to deal with changing relative phases in all of his wavetable
synthesis papers he had in the JAES).  i know you can construct all-pass
filters with long delay times inside (and sufficient feedback
coefficient) and you'll *definitely* hear a difference.  APFs only
change the phase and nothing else.

and my argument to Andrew was that it costs nothing to preserve the
phase in wavetable synthesis, so why not?  my own work (which is now
about 2 and 3 decades old) didn't even use what is commonly called the
"heterodyne oscillator" to get the wavetables.  i yanked this
time-domain waveforms directly outa the time-domain data.  Andrew would
do something like a sinusoidal modeling analysis, get both amplitude and
phase of each harmonic, and then throw the phase away before creating
the wavetables.

and I've once posted here examples of how shifting the phase of 1 harmonic 
of a sawtooth sounded very different.

I think you were even part of the debate.


probably.  perhaps i posted the same MATLAB file for discussion.

Pretty easy to check the obvious difference between a pure low sawtooth, 
and the same sawtooth with all partials starting at random phases.




"all" partials?  it's a bandlimited saw, no?  the harmonic numbers stop
at some finite number.

well, it's a (bandlimited) square wave in the example below and the
partials are changing phase in some reasonable goofy manner.  some
partials are slightly detuned up and others are slightly detuned down.
and both in such a way that the waveform slowly changes from square wave
to something unrecognizable and slowly back to square.  and, if your
playback system is nice and linear, it's unlikely you'll hear it do that
(and you keep the number of harmonics low, don't "uber-Nyquist" it).

it can be rewritten to do it for saw.

BTW, because of word-wrapping that i cannot turn off, be sure to unwrap
some of the comment lines in the MATLAB program.

--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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Re: [music-dsp] Dither video and articles


On 2/10/15 1:51 PM, Ethan Duni wrote:

So to you, that Pono player isn't snake oil?

It's more the 192kHz sampling rate that renders the Pono player into snake
oil territory. The extra bits probably aren't getting you much, but the
ridiculous sampling rate can only *hurt* audio quality, while consuming
that much more battery and storage.


that's interesting.  why does higher-than-needed sample rate hurt audio 
quality?  might not be necessary, but how does it make it worse 
(excluding the increased computational burden)?  i always think that 
analog (or continuous-time) is like having an infinite sample rate.



--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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Re: [music-dsp] Dither video and articles


On 2/10/15 1:30 PM, Didier Dambrin wrote:
Of course 24bit isn't a bad idea for intermediate files, but 32bit 
float is a better idea, even just because you don't have to normalize 
& store gain information that pretty much no app will read from the 
file. And since the price of storage is negligible these days..


can't disagree with that.  now, even with float, you can dither and 
noise shape the quantization (from double to single-precision floats), 
but the code to do so is more difficult.  and i dunno *what* to do if 
adding your dither causes, for a single sample, the exponent to change.  
it's kinda messy.  i guess you just accept that this particular sample 
will not be perfectly dithered correctly and, whatever quantization 
error *does* result, use that in the noise-shaping feedback.


--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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Re: [music-dsp] Dither video and articles

>So to you, that Pono player isn't snake oil?

It's more the 192kHz sampling rate that renders the Pono player into snake
oil territory. The extra bits probably aren't getting you much, but the
ridiculous sampling rate can only *hurt* audio quality, while consuming
that much more battery and storage.
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Re: [music-dsp] Dither video and articles


On 2/10/15 1:22 PM, Didier Dambrin wrote:
Of course, a lot of visually different waveshapes sound the same, as 
soon as the phase relationship between neighboring partials is shifted 
by the same amount.

they can be shifted by *any* amount, as long as it's static.

in fact, what do you mean by "same amount"?  same amount of time?  then 
that's just a delay.


same amount of phase?  well that *does* change the waveshape, but it can 
be any amount of phase for a perfectly periodic waveform.  when things 
get less than perfectly periodic, then you have changing harmonic 
coefficients, both in amplitude and phase.




That doesn't mean it's always the case


i agree.  if the phase changes rapidly enough, you'll hear it as a 
detuned or slightly non-harmonic partial.


i can't argue Andrew Horner's case for him (he just didn't think he 
needed to deal with changing relative phases in all of his wavetable 
synthesis papers he had in the JAES).  i know you can construct all-pass 
filters with long delay times inside (and sufficient feedback 
coefficient) and you'll *definitely* hear a difference.  APFs only 
change the phase and nothing else.


and my argument to Andrew was that it costs nothing to preserve the 
phase in wavetable synthesis, so why not?  my own work (which is now 
about 2 and 3 decades old) didn't even use what is commonly called the 
"heterodyne oscillator" to get the wavetables.  i yanked this 
time-domain waveforms directly outa the time-domain data.  Andrew would 
do something like a sinusoidal modeling analysis, get both amplitude and 
phase of each harmonic, and then throw the phase away before creating 
the wavetables.


and I've once posted here examples of how shifting the phase of 1 
harmonic of a sawtooth sounded very different.

I think you were even part of the debate.


probably.  perhaps i posted the same MATLAB file for discussion.

Pretty easy to check the obvious difference between a pure low 
sawtooth, and the same sawtooth with all partials starting at random 
phases.




"all" partials?  it's a bandlimited saw, no?  the harmonic numbers stop 
at some finite number.


well, it's a (bandlimited) square wave in the example below and the 
partials are changing phase in some reasonable goofy manner.  some 
partials are slightly detuned up and others are slightly detuned down.  
and both in such a way that the waveform slowly changes from square wave 
to something unrecognizable and slowly back to square.  and, if your 
playback system is nice and linear, it's unlikely you'll hear it do that 
(and you keep the number of harmonics low, don't "uber-Nyquist" it).


it can be rewritten to do it for saw.

BTW, because of word-wrapping that i cannot turn off, be sure to unwrap 
some of the comment lines in the MATLAB program.


--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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Re: [music-dsp] Dither video and articles

Of course 24bit isn't a bad idea for intermediate files, but 32bit float is 
a better idea, even just because you don't have to normalize & store gain 
information that pretty much no app will read from the file. And since the 
price of storage is negligible these days..





-Message d'origine- 
From: robert bristow-johnson

Sent: Tuesday, February 10, 2015 6:11 PM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles


i certainly don't think we need 24-bit and 192 kHz just for listening to
music in our living room.  but for intermediate nodes (or intermediate
files), 24-bit is not a bad idea. 


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Re: [music-dsp] Dither video and articles

Of course, a lot of visually different waveshapes sound the same, as soon as 
the phase relationship between neighboring partials is shifted by the same 
amount.


That doesn't mean it's always the case and I've once posted here examples of 
how shifting the phase of 1 harmonic of a sawtooth sounded very different.

I think you were even part of the debate.
Pretty easy to check the obvious difference between a pure low sawtooth, and 
the same sawtooth with all partials starting at random phases.






-Message d'origine- 
From: robert bristow-johnson

Sent: Tuesday, February 10, 2015 6:11 PM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles

On 2/10/15 8:49 AM, Didier Dambrin wrote:
What are you talking about - why would phase not matter? It's extremely 
important (well, phase relationship between neighboring partials).





well, it's unlikely you'll be able to hear the difference between this:

x(t) = cos(wt) - 1/3*cos(3wt) + 1/5*cos(5wt) - 1/7*cos(7wt)

and this:

x(t) = cos(wt) + 1/3*cos(3wt) + 1/5*cos(5wt) + 1/7*cos(7wt)

yet the waveshapes are much different.

so if you have MATLAB or Octave, try this file out and see what you can
hear.  look at the waveforms and see how different they are.

%
%   square_phase.m
%
%   a test to see if we can really hear phase changes
%   in the harmonics of a Nyquist limited square wave.
%
%   (c) 2004 r...@audioimagination.com <mailto:r...@audioimagination.com>
%

if ~exist('Fs', 'var')
 Fs = 44100  % sample rate, Hz
end

if ~exist('f0', 'var')
 f0 = 110.25 % fundamental freq, Hz
end

if ~exist('tone_duration', 'var')
 tone_duration = 2.0 % seconds
end

if ~exist('change_rate', 'var')
 change_rate = 1.0   % Hz
end

if ~exist('max_harmonic', 'var')
 max_harmonic = floor((Fs/2)/f0) - 1
end

if ~exist('amplitude_factor', 'var')
 amplitude_factor = 0.25 % this just keeps things from
clipping
end

if ~exist('outFile', 'var')
 outFile = 'square_phase.wav'
end


   % make sure we don't uber-Nyquist
anything
max_harmonic = min(max_harmonic, floor((Fs/2)/f0)-1);

t = linspace((-1/4)/f0, tone_duration-(1/4)/f0, Fs*tone_duration+1);

detune = change_rate;

x = cos(2*pi*f0*t);  % start with 1st harmonic

n = 3;   % continue with 3rd harmonic while
(n <= max_harmonic)
 if ((n-1) == 4*floor((n-1)/4))   % lessee if it's an "even" or
"odd" term
 x = x + (1/n)*cos(2*pi*n*f0*t);
  else
 x = x - (1/n)*cos(2*pi*(n*f0+detune)*t);
 detune = -detune;% comment this line in an see some
 end  % funky intermediate waveforms
 n = n + 2;   % continue with next odd harmonic
end

x = amplitude_factor*x;

% x = sin((pi/2)*x);   % toss in a little soft clipping

plot(t, x);  % see
sound(x, Fs);% hear
wavwrite(x, Fs, outFile);% remember






16 bits is just barely enough for high-quality audio.


So to you, that Pono player isn't snake oil?


well, Vicki is the high-res guru here.

i certainly don't think we need 24-bit and 192 kHz just for listening to
music in our living room.  but for intermediate nodes (or intermediate
files), 24-bit is not a bad idea.  and if you have space or bandwidth to
burn, why not, say, 96 kHz.  then people can't complain about the
scrunching of the bell curve near Nyquist they get with "cookbook EQ".

for a high-quality audio and music signal processor, i think that 16-bit
pre-emphasized files (for sampled sounds or waveforms) is the minimum i
want, 16-bit or more ADC and DAC, and 24-bit internal nodes for
processing is the minimum i would want to not feel "cheap" about it.  if
i were to use an ADI Blackfin (i never have) to process music and
better-than-voice audio, i would end up doing a lot of double-precision
math.

BTW, at this:
http://www.aes.org/events/125/tutorials/session.cfm?code=T19 i
demonstrated how good 7-bit audio sounds in a variety of different
formats, including fixed, float (with 3 exponent bits and 4 mantissa
bits), and block floating point (actually that was 7.001 bits per
sample), dithered and not, noise-shaped and not.  but i still wouldn't
want to listen to 7-bit audio if i had CD.

well dithered and noise-shaped 16-bits at 44.1 kHz is good enough for
me.  i might not be able to hear much wrong with 128 kbit/sec MP3, but i
still like CD audio better.




Besides, if it had mattered so much, non-linear (mu/A-law) encoding could 
have applied to 16bit as well..




naw, then you get a sorta noise amplitude modulation with

Re: [music-dsp] Dither video and articles


On 2/10/15 8:49 AM, Didier Dambrin wrote:
What are you talking about - why would phase not matter? It's 
extremely important (well, phase relationship between neighboring 
partials).





well, it's unlikely you'll be able to hear the difference between this:

x(t) = cos(wt) - 1/3*cos(3wt) + 1/5*cos(5wt) - 1/7*cos(7wt)

and this:

x(t) = cos(wt) + 1/3*cos(3wt) + 1/5*cos(5wt) + 1/7*cos(7wt)

yet the waveshapes are much different.

so if you have MATLAB or Octave, try this file out and see what you can 
hear.  look at the waveforms and see how different they are.


%
%   square_phase.m
%
%   a test to see if we can really hear phase changes
%   in the harmonics of a Nyquist limited square wave.
%
%   (c) 2004 r...@audioimagination.com 
%

if ~exist('Fs', 'var')
 Fs = 44100  % sample rate, Hz
end

if ~exist('f0', 'var')
 f0 = 110.25 % fundamental freq, Hz
end

if ~exist('tone_duration', 'var')
 tone_duration = 2.0 % seconds
end

if ~exist('change_rate', 'var')
 change_rate = 1.0   % Hz
end

if ~exist('max_harmonic', 'var')
 max_harmonic = floor((Fs/2)/f0) - 1
end

if ~exist('amplitude_factor', 'var')
 amplitude_factor = 0.25 % this just keeps things from 
clipping

end

if ~exist('outFile', 'var')
 outFile = 'square_phase.wav'
end


   % make sure we don't uber-Nyquist 
anything

max_harmonic = min(max_harmonic, floor((Fs/2)/f0)-1);

t = linspace((-1/4)/f0, tone_duration-(1/4)/f0, Fs*tone_duration+1);

detune = change_rate;

x = cos(2*pi*f0*t);  % start with 1st harmonic

n = 3;   % continue with 3rd harmonic while 
(n <= max_harmonic)
 if ((n-1) == 4*floor((n-1)/4))   % lessee if it's an "even" or 
"odd" term

 x = x + (1/n)*cos(2*pi*n*f0*t);
  else
 x = x - (1/n)*cos(2*pi*(n*f0+detune)*t);
 detune = -detune;% comment this line in an see some
 end  % funky intermediate waveforms
 n = n + 2;   % continue with next odd harmonic
end

x = amplitude_factor*x;

% x = sin((pi/2)*x);   % toss in a little soft clipping

plot(t, x);  % see
sound(x, Fs);% hear
wavwrite(x, Fs, outFile);% remember






16 bits is just barely enough for high-quality audio.


So to you, that Pono player isn't snake oil?


well, Vicki is the high-res guru here.

i certainly don't think we need 24-bit and 192 kHz just for listening to 
music in our living room.  but for intermediate nodes (or intermediate 
files), 24-bit is not a bad idea.  and if you have space or bandwidth to 
burn, why not, say, 96 kHz.  then people can't complain about the 
scrunching of the bell curve near Nyquist they get with "cookbook EQ".


for a high-quality audio and music signal processor, i think that 16-bit 
pre-emphasized files (for sampled sounds or waveforms) is the minimum i 
want, 16-bit or more ADC and DAC, and 24-bit internal nodes for 
processing is the minimum i would want to not feel "cheap" about it.  if 
i were to use an ADI Blackfin (i never have) to process music and 
better-than-voice audio, i would end up doing a lot of double-precision 
math.


BTW, at this: 
http://www.aes.org/events/125/tutorials/session.cfm?code=T19 i 
demonstrated how good 7-bit audio sounds in a variety of different 
formats, including fixed, float (with 3 exponent bits and 4 mantissa 
bits), and block floating point (actually that was 7.001 bits per 
sample), dithered and not, noise-shaped and not.  but i still wouldn't 
want to listen to 7-bit audio if i had CD.


well dithered and noise-shaped 16-bits at 44.1 kHz is good enough for 
me.  i might not be able to hear much wrong with 128 kbit/sec MP3, but i 
still like CD audio better.





Besides, if it had mattered so much, non-linear (mu/A-law) encoding 
could have applied to 16bit as well..




naw, then you get a sorta noise amplitude modulation with a signal of 
roughly constant amplitude.  and there are much better ways to do 
optimal bit reduction than companding.  companding is a quick and easy 
way they did it back in the old Bell System days.  and, even in 
companding, arcsinh() and sinh() would be smoother mapping than either 
mu or A-law.



--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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Re: [music-dsp] Dither video and articles

What are you talking about - why would phase not matter? It's extremely 
important (well, phase relationship between neighboring partials).





16 bits is just barely enough for high-quality audio.


So to you, that Pono player isn't snake oil?

Besides, if it had mattered so much, non-linear (mu/A-law) encoding could 
have applied to 16bit as well..






-Message d'origine- 
From: robert bristow-johnson

Sent: Tuesday, February 10, 2015 2:37 PM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles

On 2/9/15 10:19 PM, Nigel Redmon wrote:
But it matters, because the whole point of dithering to 16bit depends on 
how common that ability is.
Depends on how common? I’m not sure what qualifies for common, but if it’s 
1 in 100, or 5 in 100, it’s still a no-brainer because it costs nothing, 
effectively.


i have had a similar argument with Andrew Horner about tossing phase
information outa the line spectrum of wavetables for wavetable
synthesis.  why bother to do that?  why not just keep the phase
information and the waveshape when it costs nothing to do it.

regarding dithering and quantization, if it were me, for 32-bit or
24-bit fixed-point *intermediate* values (like multiple internal nodes
of an algorithm), simply because of the cost of dithering, i would
simply use "fraction saving", which is 1st-order noise shaping with a
zero at DC, and not dither.  or just simply round, but the fraction
saving is better and just about as cheap in computational cost.

but for quantizing to 16 bits (like for mastering a CD or a 16-bit
uncompressed .wav or .aif file), i would certainly dither and optimally
noise-shape that.  it costs a little more, but like the wavetable phase,
once you do it the ongoing costs are nothing.  and you have better data
stored in your lower resolution format.  so why not?

16 bits is just barely enough for high-quality audio.  and it wouldn't
have been if Stanley Lipshitz and John Vanderkooy and Robert Wanamaker
didn't tell us in the 80's how to extract another few more dB outa the
dynamic range of the 16-bit word.  they really rescued the 80 minute Red
Book CD.

--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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Re: [music-dsp] Dither video and articles


On 2/9/15 10:19 PM, Nigel Redmon wrote:

But it matters, because the whole point of dithering to 16bit depends on how 
common that ability is.

Depends on how common? I’m not sure what qualifies for common, but if it’s 1 in 
100, or 5 in 100, it’s still a no-brainer because it costs nothing, effectively.


i have had a similar argument with Andrew Horner about tossing phase 
information outa the line spectrum of wavetables for wavetable 
synthesis.  why bother to do that?  why not just keep the phase 
information and the waveshape when it costs nothing to do it.


regarding dithering and quantization, if it were me, for 32-bit or 
24-bit fixed-point *intermediate* values (like multiple internal nodes 
of an algorithm), simply because of the cost of dithering, i would 
simply use "fraction saving", which is 1st-order noise shaping with a 
zero at DC, and not dither.  or just simply round, but the fraction 
saving is better and just about as cheap in computational cost.


but for quantizing to 16 bits (like for mastering a CD or a 16-bit 
uncompressed .wav or .aif file), i would certainly dither and optimally 
noise-shape that.  it costs a little more, but like the wavetable phase, 
once you do it the ongoing costs are nothing.  and you have better data 
stored in your lower resolution format.  so why not?


16 bits is just barely enough for high-quality audio.  and it wouldn't 
have been if Stanley Lipshitz and John Vanderkooy and Robert Wanamaker 
didn't tell us in the 80's how to extract another few more dB outa the 
dynamic range of the 16-bit word.  they really rescued the 80 minute Red 
Book CD.


--

r b-j  r...@audioimagination.com

"Imagination is more important than knowledge."



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Re: [music-dsp] Dither video and articles

Interestingly, I wasn't gonna suggest that a possible cause could have been 
a compressor built-in the soundcard, because.. why would a soundcard even do 
that..


However.. I've polled some people in our forum with this same test, and one 
guy could hear it. But it turns out that he owns an X-Fi, and it does 
feature automatic gain compensation, which was on for him. Owning the same 
soundcard, I turned it on, and yes, that made the noise at -80dB rather 
clear.


I'm not saying it's what's happening for you, but are you 100% sure of 
everything the signal goes through in your system?



This said, the existence of a built-in compressor in a soundcard.. that 
alone might be a point for dithering, if the common end listener leaves that 
kind of thing on.





-Message d'origine- 
From: Andrew Simper

Sent: Tuesday, February 10, 2015 6:52 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Hi Didier,

I count myself as having good hearing, I always wear ear protection at
any gigs / loud events and have always done so. My hearing is very
important to me since it is essential for my livelihood.

I made a new test, a 440 hz sine wave with three 0.25 second white
noise bursts -66 dB, -72 dB and -75 dB below the sine (which is at -6
dBFS). I can hear the first one very clearly, then just hear the
second one. I can't actually hear the hiss of the third one but I can
hear the amplitude of the sine wave fractionally lowering when the
actual amplitude of the test sine remains constant, I don't know why
this is but that's how I hear it.

You will clearly see where the white noise bursts are if you use some
sort of FFT display, but please just have a listen first and try and
pick where each (3 total) are in the file:

www.cytomic.com/files/dsp/border-of-hearing.wav

For the other way around, a constant noise file and with bursts of 440
hz sine waves, the sine has to be very loud before I can hear it, up
around -28 dB from memory. Noise added to a sine wave is much easier
to pick, which is why I think low pass filtered tones that are largely
sine like in nature are the border case for dither.

All the best,

Andy


-- cytomic -- sound music software --


On 10 February 2015 at 10:56, Didier Dambrin  wrote:

I'm having a hard time finding anyone who could hear past the -72dB noise,
here around.

Really, either you have super-ears, or the cause is (technically) 
somewhere
else. But it matters, because the whole point of dithering to 16bit 
depends

on how common that ability is.




-Message d'origine- From: Andrew Simper
Sent: Saturday, February 07, 2015 2:08 PM

To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

On 7 February 2015 at 03:52, Didier Dambrin  wrote:


It was just several times the same fading in/out noise at different
levels,
just to see if you hear quieter things than I do, I thought you'd have
guessed that.

https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing
(0dB, -36dB, -54dB, -66dB, -72dB, -78dB)

Here if I make the starting noise annoying, then I hear the first 4 
parts,

until 18:00. Thus, if 0dB is my threshold of annoyance, I can't hear
-72dB.

So you hear it at -78dB? Would be interesting to know how many can, and 
if

it's subjective or a matter of testing environment (the variable already
being the 0dB "annoyance" starting point)



Yep, I could hear all of them, and the time I couldn't hear the hiss
any more as at the 28.7 second mark, just before the end of the file.
For reference this noise blast sounded much louder than the bass tone
that Nigel posted when both were normalised, I had my headphones amp
at -18 dB so the first noise peak was loud but not uncomfortable.

I thought it was an odd test since the test file just stopped before I
couldn't hear the LFO amplitude modulation cycles, so I wasn't sure
what you were trying to prove!

All the best,

Andy





-Message d'origine- From: Andrew Simper
Sent: Friday, February 06, 2015 3:21 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Sorry, you said until, which is even more confusing. There are
multiple points when I hear the noise until since it sounds like the
noise is modulated in amplitude by a sine like LFO for the entire
file, so the volume of the noise ramps up and down in a cyclic manner.
The last ramping I hear fades out at around the 28.7 second mark when
it is hard to tell if it just ramps out at that point or is just on
the verge of ramping up again and then the file ends at 28.93 seconds.
I have not tried to measure the LFO wavelength or any other such
things, this is just going on listening alone.

All the best,

Andrew Simper



On 6 February 2015 at 22:01, Andrew Simper  wrote:



On 6 February 2015 at 17:32, Didier Dambrin  wrote:



J

[music-dsp] Dither video and articles

2015-02-10 Thread master...@telia.com

Andreas:

>The hearing threshold apparently is at around 10dbSPL

The generally accepted hearing threshold is in fact around 0 dB SPL.

Around 3 kHz it is around - 6 dB SPL.

-- 
Best regards,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: master...@telia.com

Learn from the mistakes of others, you can never live long enough to
make them all yourself.    -   John Luther

(\__/)
(='.'=)
(")_(") Smurfen:RIP







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Re: [music-dsp] Dither video and articles

2015-02-10 Thread Andreas Beisler

Didier, afaik the pain threshold for humans is at 120dBSPL. And there 
have been rock concerts that had an even louder level than that.


The hearing threshold apparently is at around 10dbSPL. Taking your 
-72dBFS truncation noise levels, that gives 82dbSPL as the threshold of 
being able to hear the truncation noise. That's almost 40dbSPL away from 
the pain threshold.


I am sure loads of people are listening to their stuff at higher levels 
than 82dbSPL from time to time on their home stereo. Imho this use case 
alone justifies dithering more than enough, doesn't it?


Andreas



On 2/10/2015 3:56 AM, Didier Dambrin wrote:

I'm having a hard time finding anyone who could hear past the -72dB
noise, here around.

Really, either you have super-ears, or the cause is (technically)
somewhere else. But it matters, because the whole point of dithering to
16bit depends on how common that ability is.




-Message d'origine- From: Andrew Simper
Sent: Saturday, February 07, 2015 2:08 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

On 7 February 2015 at 03:52, Didier Dambrin  wrote:

It was just several times the same fading in/out noise at different
levels,
just to see if you hear quieter things than I do, I thought you'd have
guessed that.
https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing

(0dB, -36dB, -54dB, -66dB, -72dB, -78dB)

Here if I make the starting noise annoying, then I hear the first 4
parts,
until 18:00. Thus, if 0dB is my threshold of annoyance, I can't hear
-72dB.

So you hear it at -78dB? Would be interesting to know how many can,
and if
it's subjective or a matter of testing environment (the variable already
being the 0dB "annoyance" starting point)


Yep, I could hear all of them, and the time I couldn't hear the hiss
any more as at the 28.7 second mark, just before the end of the file.
For reference this noise blast sounded much louder than the bass tone
that Nigel posted when both were normalised, I had my headphones amp
at -18 dB so the first noise peak was loud but not uncomfortable.

I thought it was an odd test since the test file just stopped before I
couldn't hear the LFO amplitude modulation cycles, so I wasn't sure
what you were trying to prove!

All the best,

Andy





-Message d'origine- From: Andrew Simper
Sent: Friday, February 06, 2015 3:21 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Sorry, you said until, which is even more confusing. There are
multiple points when I hear the noise until since it sounds like the
noise is modulated in amplitude by a sine like LFO for the entire
file, so the volume of the noise ramps up and down in a cyclic manner.
The last ramping I hear fades out at around the 28.7 second mark when
it is hard to tell if it just ramps out at that point or is just on
the verge of ramping up again and then the file ends at 28.93 seconds.
I have not tried to measure the LFO wavelength or any other such
things, this is just going on listening alone.

All the best,

Andrew Simper



On 6 February 2015 at 22:01, Andrew Simper  wrote:


On 6 February 2015 at 17:32, Didier Dambrin  wrote:


Just out of curiosity, until which point do you hear the noise in this
little test (a 32bit float wav), starting from a bearable first part?


https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing




I hear noise immediately in that recording, it's hard to tell exactly
the time I can first hear it since there is some latency from when I
press play to when the sound starts, but as far as I can tell it is
straight away. Why do you ask such silly questions?

All the best,

Andrew Simper


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Re: [music-dsp] Dither video and articles

>An audio engineer doesn't work for himself, so I don't see your point.

Well, I think that you probably do, but if you really don’t, set about chatting 
individually with such people to convince them that they can’t hear and don’t 
need dither at 16-bit, and you’ll get the point soon enough ;-)

But I don’t want to give you the impression I’m arguing, just discussing. I 
don’t feel we’re that far apart, in general.


> On Feb 9, 2015, at 10:12 PM, Didier Dambrin  wrote:
> 
> Well if it's 1 in 100, then dither using whatever is available & forget it. 
> But if it's 50 in 100, then I'd say it's still worth getting interested in 
> the best dithering algo's, or developping them further.
> In fact, if it happens to be 50 in 100, then I'd even go as far as saying 
> that delivering music to the world in 24bit format is NOT stupid and that 
> Neil Young's music player isn't just a lame marketing ploy.
> 
> 
> An audio engineer doesn't work for himself, so I don't see your point. An 
> audio engineer's most important job is also mastering, which generally 
> involves heavy compression & other rather destructive processes.
> To me, if an audio engineer dithers, it's more related to that compulsive 
> obsession about well-rounded things, that us programmers "suffer" from as 
> well. I bet many programmers here, when having to decide about parameter 
> values, will go for 1. no decimals if that works, 2. even numbers if that 
> works, 3. powers of 2 if that works. For no other reason than imaginary 
> perfection, so it's a form of superstition.
> 
> But yes, you're right that dithering has a selling point, if the goal is to 
> sell it to engineers. But then it's a debate more about marketing than 
> "science". Hey, it doesn't even need to do anything to be sellable.
> 
> 
> Personally, I think it'd be way more interesting to know more about this side 
> of perception. There's no mystery about the humanly audible frequency range, 
> and how it varies with age. Looks like there still is about levels?
> Afterall, my ears aren't in perfect shape, I happen to have hyperacusis of 
> bass (that, or the rest of the world doesn't hear bass loud enough).
> 
> It would also be interesting in other domains of DSP, because it's, for ex, 
> quite common to use waveshaping tables to save computation - the precision of 
> those tables then doesn't depend on our own perception, but the accepted one. 
> We use a lot of expensive trigonometry functions, and it has become quite 
> common to use low-precision algos to spare CPU. I've always done this 
> according to my ears, not according to charts.
> 
> 
> 
> 
> -Message d'origine- From: Nigel Redmon
> Sent: Tuesday, February 10, 2015 4:19 AM
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
> 
>> But it matters, because the whole point of dithering to 16bit depends on how 
>> common that ability is.
> 
> Depends on how common? I’m not sure what qualifies for common, but if it’s 1 
> in 100, or 5 in 100, it’s still a no-brainer because it costs nothing, 
> effectively.
> 
> But more importantly, I don’t think you’re impressed by my point that it’s 
> the audio engineers, the folks making the music, that are in the best 
> position to hear it, and to do something about it. There are the ones 
> listening carefully, in studios built to be quiet and lack reflections and 
> resonances that might mask things, on revealing monitors and with ample 
> power. I don’t think that you understand that it’s these guys who are not 
> going to let their work go out the door with grit on it, even if it’s below 
> -90 dB. You wouldn’t get many sympathetic ears among them if you advocated 
> that they cease this dithering nonsense :-) I get enough grief about telling 
> them that dither at 24-bit is useless.
> 
> How common it is for for the average listener is immaterial. It’s not done 
> for the average listener.
> 
> 
>> On Feb 9, 2015, at 6:56 PM, Didier Dambrin  wrote:
>> 
>> I'm having a hard time finding anyone who could hear past the -72dB noise, 
>> here around.
>> 
>> Really, either you have super-ears, or the cause is (technically) somewhere 
>> else. But it matters, because the whole point of dithering to 16bit depends 
>> on how common that ability is.
>> 
>> 
>> 
>> 
>> -Message d'origine- From: Andrew Simper
>> Sent: Saturday, February 07, 2015 2:08 PM
>> To: A discussion list for music-related DSP
>> Subject: Re: [music-dsp] Dither video and articles
&

Re: [music-dsp] Dither video and articles

2015-02-09 Thread Didier Dambrin

Well if it's 1 in 100, then dither using whatever is available & forget it. 
But if it's 50 in 100, then I'd say it's still worth getting interested in 
the best dithering algo's, or developping them further.
In fact, if it happens to be 50 in 100, then I'd even go as far as saying 
that delivering music to the world in 24bit format is NOT stupid and that 
Neil Young's music player isn't just a lame marketing ploy.



An audio engineer doesn't work for himself, so I don't see your point. An 
audio engineer's most important job is also mastering, which generally 
involves heavy compression & other rather destructive processes.
To me, if an audio engineer dithers, it's more related to that compulsive 
obsession about well-rounded things, that us programmers "suffer" from as 
well. I bet many programmers here, when having to decide about parameter 
values, will go for 1. no decimals if that works, 2. even numbers if that 
works, 3. powers of 2 if that works. For no other reason than imaginary 
perfection, so it's a form of superstition.


But yes, you're right that dithering has a selling point, if the goal is to 
sell it to engineers. But then it's a debate more about marketing than 
"science". Hey, it doesn't even need to do anything to be sellable.



Personally, I think it'd be way more interesting to know more about this 
side of perception. There's no mystery about the humanly audible frequency 
range, and how it varies with age. Looks like there still is about levels?
Afterall, my ears aren't in perfect shape, I happen to have hyperacusis of 
bass (that, or the rest of the world doesn't hear bass loud enough).


It would also be interesting in other domains of DSP, because it's, for ex, 
quite common to use waveshaping tables to save computation - the precision 
of those tables then doesn't depend on our own perception, but the accepted 
one. We use a lot of expensive trigonometry functions, and it has become 
quite common to use low-precision algos to spare CPU. I've always done this 
according to my ears, not according to charts.





-Message d'origine----- 
From: Nigel Redmon

Sent: Tuesday, February 10, 2015 4:19 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

But it matters, because the whole point of dithering to 16bit depends on 
how common that ability is.


Depends on how common? I’m not sure what qualifies for common, but if it’s 1 
in 100, or 5 in 100, it’s still a no-brainer because it costs nothing, 
effectively.


But more importantly, I don’t think you’re impressed by my point that it’s 
the audio engineers, the folks making the music, that are in the best 
position to hear it, and to do something about it. There are the ones 
listening carefully, in studios built to be quiet and lack reflections and 
resonances that might mask things, on revealing monitors and with ample 
power. I don’t think that you understand that it’s these guys who are not 
going to let their work go out the door with grit on it, even if it’s 
below -90 dB. You wouldn’t get many sympathetic ears among them if you 
advocated that they cease this dithering nonsense :-) I get enough grief 
about telling them that dither at 24-bit is useless.


How common it is for for the average listener is immaterial. It’s not done 
for the average listener.




On Feb 9, 2015, at 6:56 PM, Didier Dambrin  wrote:

I'm having a hard time finding anyone who could hear past the -72dB noise, 
here around.


Really, either you have super-ears, or the cause is (technically) 
somewhere else. But it matters, because the whole point of dithering to 
16bit depends on how common that ability is.





-----Message d'origine- From: Andrew Simper
Sent: Saturday, February 07, 2015 2:08 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

On 7 February 2015 at 03:52, Didier Dambrin  wrote:
It was just several times the same fading in/out noise at different 
levels,

just to see if you hear quieter things than I do, I thought you'd have
guessed that.
https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing
(0dB, -36dB, -54dB, -66dB, -72dB, -78dB)

Here if I make the starting noise annoying, then I hear the first 4 
parts,
until 18:00. Thus, if 0dB is my threshold of annoyance, I can't 
hear -72dB.


So you hear it at -78dB? Would be interesting to know how many can, and 
if

it's subjective or a matter of testing environment (the variable already
being the 0dB "annoyance" starting point)


Yep, I could hear all of them, and the time I couldn't hear the hiss
any more as at the 28.7 second mark, just before the end of the file.
For reference this noise blast sounded much louder than the bass tone
that Nigel posted when both were normali

Re: [music-dsp] Dither video and articles

2015-02-09 Thread Andrew Simper

Hi Didier,

I count myself as having good hearing, I always wear ear protection at
any gigs / loud events and have always done so. My hearing is very
important to me since it is essential for my livelihood.

I made a new test, a 440 hz sine wave with three 0.25 second white
noise bursts -66 dB, -72 dB and -75 dB below the sine (which is at -6
dBFS). I can hear the first one very clearly, then just hear the
second one. I can't actually hear the hiss of the third one but I can
hear the amplitude of the sine wave fractionally lowering when the
actual amplitude of the test sine remains constant, I don't know why
this is but that's how I hear it.

You will clearly see where the white noise bursts are if you use some
sort of FFT display, but please just have a listen first and try and
pick where each (3 total) are in the file:

www.cytomic.com/files/dsp/border-of-hearing.wav

For the other way around, a constant noise file and with bursts of 440
hz sine waves, the sine has to be very loud before I can hear it, up
around -28 dB from memory. Noise added to a sine wave is much easier
to pick, which is why I think low pass filtered tones that are largely
sine like in nature are the border case for dither.

All the best,

Andy


-- cytomic -- sound music software --


On 10 February 2015 at 10:56, Didier Dambrin  wrote:
> I'm having a hard time finding anyone who could hear past the -72dB noise,
> here around.
>
> Really, either you have super-ears, or the cause is (technically) somewhere
> else. But it matters, because the whole point of dithering to 16bit depends
> on how common that ability is.
>
>
>
>
> -Message d'origine- From: Andrew Simper
> Sent: Saturday, February 07, 2015 2:08 PM
>
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
>
> On 7 February 2015 at 03:52, Didier Dambrin  wrote:
>>
>> It was just several times the same fading in/out noise at different
>> levels,
>> just to see if you hear quieter things than I do, I thought you'd have
>> guessed that.
>>
>> https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing
>> (0dB, -36dB, -54dB, -66dB, -72dB, -78dB)
>>
>> Here if I make the starting noise annoying, then I hear the first 4 parts,
>> until 18:00. Thus, if 0dB is my threshold of annoyance, I can't hear
>> -72dB.
>>
>> So you hear it at -78dB? Would be interesting to know how many can, and if
>> it's subjective or a matter of testing environment (the variable already
>> being the 0dB "annoyance" starting point)
>
>
> Yep, I could hear all of them, and the time I couldn't hear the hiss
> any more as at the 28.7 second mark, just before the end of the file.
> For reference this noise blast sounded much louder than the bass tone
> that Nigel posted when both were normalised, I had my headphones amp
> at -18 dB so the first noise peak was loud but not uncomfortable.
>
> I thought it was an odd test since the test file just stopped before I
> couldn't hear the LFO amplitude modulation cycles, so I wasn't sure
> what you were trying to prove!
>
> All the best,
>
> Andy
>
>
>
>
>> -Message d'origine- From: Andrew Simper
>> Sent: Friday, February 06, 2015 3:21 PM
>> To: A discussion list for music-related DSP
>> Subject: Re: [music-dsp] Dither video and articles
>>
>> Sorry, you said until, which is even more confusing. There are
>> multiple points when I hear the noise until since it sounds like the
>> noise is modulated in amplitude by a sine like LFO for the entire
>> file, so the volume of the noise ramps up and down in a cyclic manner.
>> The last ramping I hear fades out at around the 28.7 second mark when
>> it is hard to tell if it just ramps out at that point or is just on
>> the verge of ramping up again and then the file ends at 28.93 seconds.
>> I have not tried to measure the LFO wavelength or any other such
>> things, this is just going on listening alone.
>>
>> All the best,
>>
>> Andrew Simper
>>
>>
>>
>> On 6 February 2015 at 22:01, Andrew Simper  wrote:
>>>
>>>
>>> On 6 February 2015 at 17:32, Didier Dambrin  wrote:
>>>>
>>>>
>>>> Just out of curiosity, until which point do you hear the noise in this
>>>> little test (a 32bit float wav), starting from a bearable first part?
>>>>
>>>>
>>>>
>>>> https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing
>>>
>>>
>>>
>>> I hear noise immediately in that recording, it's hard to t

Re: [music-dsp] Dither video and articles

>But it matters, because the whole point of dithering to 16bit depends on how 
>common that ability is.

Depends on how common? I’m not sure what qualifies for common, but if it’s 1 in 
100, or 5 in 100, it’s still a no-brainer because it costs nothing, effectively.

But more importantly, I don’t think you’re impressed by my point that it’s the 
audio engineers, the folks making the music, that are in the best position to 
hear it, and to do something about it. There are the ones listening carefully, 
in studios built to be quiet and lack reflections and resonances that might 
mask things, on revealing monitors and with ample power. I don’t think that you 
understand that it’s these guys who are not going to let their work go out the 
door with grit on it, even if it’s below -90 dB. You wouldn’t get many 
sympathetic ears among them if you advocated that they cease this dithering 
nonsense :-) I get enough grief about telling them that dither at 24-bit is 
useless.

How common it is for for the average listener is immaterial. It’s not done for 
the average listener.


> On Feb 9, 2015, at 6:56 PM, Didier Dambrin  wrote:
> 
> I'm having a hard time finding anyone who could hear past the -72dB noise, 
> here around.
> 
> Really, either you have super-ears, or the cause is (technically) somewhere 
> else. But it matters, because the whole point of dithering to 16bit depends 
> on how common that ability is.
> 
> 
> 
> 
> -Message d'origine- From: Andrew Simper
> Sent: Saturday, February 07, 2015 2:08 PM
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
> 
> On 7 February 2015 at 03:52, Didier Dambrin  wrote:
>> It was just several times the same fading in/out noise at different levels,
>> just to see if you hear quieter things than I do, I thought you'd have
>> guessed that.
>> https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing
>> (0dB, -36dB, -54dB, -66dB, -72dB, -78dB)
>> 
>> Here if I make the starting noise annoying, then I hear the first 4 parts,
>> until 18:00. Thus, if 0dB is my threshold of annoyance, I can't hear -72dB.
>> 
>> So you hear it at -78dB? Would be interesting to know how many can, and if
>> it's subjective or a matter of testing environment (the variable already
>> being the 0dB "annoyance" starting point)
> 
> Yep, I could hear all of them, and the time I couldn't hear the hiss
> any more as at the 28.7 second mark, just before the end of the file.
> For reference this noise blast sounded much louder than the bass tone
> that Nigel posted when both were normalised, I had my headphones amp
> at -18 dB so the first noise peak was loud but not uncomfortable.
> 
> I thought it was an odd test since the test file just stopped before I
> couldn't hear the LFO amplitude modulation cycles, so I wasn't sure
> what you were trying to prove!
> 
> All the best,
> 
> Andy
> 
> 
> 
> 
>> -Message d'origine- From: Andrew Simper
>> Sent: Friday, February 06, 2015 3:21 PM
>> To: A discussion list for music-related DSP
>> Subject: Re: [music-dsp] Dither video and articles
>> 
>> Sorry, you said until, which is even more confusing. There are
>> multiple points when I hear the noise until since it sounds like the
>> noise is modulated in amplitude by a sine like LFO for the entire
>> file, so the volume of the noise ramps up and down in a cyclic manner.
>> The last ramping I hear fades out at around the 28.7 second mark when
>> it is hard to tell if it just ramps out at that point or is just on
>> the verge of ramping up again and then the file ends at 28.93 seconds.
>> I have not tried to measure the LFO wavelength or any other such
>> things, this is just going on listening alone.
>> 
>> All the best,
>> 
>> Andrew Simper
>> 
>> 
>> 
>> On 6 February 2015 at 22:01, Andrew Simper  wrote:
>>> 
>>> On 6 February 2015 at 17:32, Didier Dambrin  wrote:
>>>> 
>>>> Just out of curiosity, until which point do you hear the noise in this
>>>> little test (a 32bit float wav), starting from a bearable first part?
>>>> 
>>>> 
>>>> https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing
>>> 
>>> 
>>> I hear noise immediately in that recording, it's hard to tell exactly
>>> the time I can first hear it since there is some latency from when I
>>> press play to when the sound starts, but as far as I can tell it is
>>> straight away. Why do you ask such silly questions?
>>> 
>&

Re: [music-dsp] Dither video and articles

2015-02-09 Thread Didier Dambrin

I'm having a hard time finding anyone who could hear past the -72dB noise, 
here around.


Really, either you have super-ears, or the cause is (technically) somewhere 
else. But it matters, because the whole point of dithering to 16bit depends 
on how common that ability is.





-Message d'origine- 
From: Andrew Simper

Sent: Saturday, February 07, 2015 2:08 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

On 7 February 2015 at 03:52, Didier Dambrin  wrote:
It was just several times the same fading in/out noise at different 
levels,

just to see if you hear quieter things than I do, I thought you'd have
guessed that.
https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing
(0dB, -36dB, -54dB, -66dB, -72dB, -78dB)

Here if I make the starting noise annoying, then I hear the first 4 parts,
until 18:00. Thus, if 0dB is my threshold of annoyance, I can't 
hear -72dB.


So you hear it at -78dB? Would be interesting to know how many can, and if
it's subjective or a matter of testing environment (the variable already
being the 0dB "annoyance" starting point)


Yep, I could hear all of them, and the time I couldn't hear the hiss
any more as at the 28.7 second mark, just before the end of the file.
For reference this noise blast sounded much louder than the bass tone
that Nigel posted when both were normalised, I had my headphones amp
at -18 dB so the first noise peak was loud but not uncomfortable.

I thought it was an odd test since the test file just stopped before I
couldn't hear the LFO amplitude modulation cycles, so I wasn't sure
what you were trying to prove!

All the best,

Andy





-Message d'origine- From: Andrew Simper
Sent: Friday, February 06, 2015 3:21 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Sorry, you said until, which is even more confusing. There are
multiple points when I hear the noise until since it sounds like the
noise is modulated in amplitude by a sine like LFO for the entire
file, so the volume of the noise ramps up and down in a cyclic manner.
The last ramping I hear fades out at around the 28.7 second mark when
it is hard to tell if it just ramps out at that point or is just on
the verge of ramping up again and then the file ends at 28.93 seconds.
I have not tried to measure the LFO wavelength or any other such
things, this is just going on listening alone.

All the best,

Andrew Simper



On 6 February 2015 at 22:01, Andrew Simper  wrote:


On 6 February 2015 at 17:32, Didier Dambrin  wrote:


Just out of curiosity, until which point do you hear the noise in this
little test (a 32bit float wav), starting from a bearable first part?


https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing



I hear noise immediately in that recording, it's hard to tell exactly
the time I can first hear it since there is some latency from when I
press play to when the sound starts, but as far as I can tell it is
straight away. Why do you ask such silly questions?

All the best,

Andrew Simper


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Re: [music-dsp] Dither video and articles

I’m thankful for Andy posting that clear explanation too. Sometimes I 
understate things—when I said that it would be “pretty hard to avoid” having 
ample gaussian noise to self-dither in the A/D process, I was thinking 
cryogenics (LOL).


> On Feb 9, 2015, at 7:54 AM, Vicki Melchior  wrote:
> 
> That's a clear explanation of the self-dither assumed in A/D conversion, 
> thanks for posting it. 
> 
> Vicki
> 
> On Feb 8, 2015, at 9:11 PM, Andrew Simper wrote:
> 
>> Vicki,
>> 
>> If you look at the limits of what is possible in a real world ADC
>> there is a certain amount of noise in any electrical system due to
>> gaussian thermal noise:
>> http://en.wikipedia.org/wiki/Johnson%E2%80%93Nyquist_noise
>> 
>> For example if you look at an instrument / measurement grade ADC like
>> this: 
>> http://www.prismsound.com/test_measure/products_subs/dscope/dscope_spec.php
>> They publish figures of a residual noise floor of 1.4 uV, which they
>> say is -115 dBu. So if you digitise a 1 V peak (2 V peak to peak) sine
>> wave with a 24-bit ADC then you will have hiss (which includes a large
>> portion of gaussian noise) at around the 20 bit mark, so you will have
>> 4-bits of hiss to self dither. This has nothing to do with microphones
>> or noise in air, this is in the near perfect case of transmission via
>> a well shielded differential cable transferring the voltage directly
>> to the ADC.
>> 
>> All the best,
>> 
>> Andy
>> -- cytomic -- sound music software --
>> 
>> 
>> On 9 February 2015 at 00:09, Vicki Melchior  wrote:
>>> I have no argument at all with the cheap high-pass TPDF dither; whenever it 
>>> was published the original authors undoubtedly verified that the moment 
>>> decoupling occurred, as you say.  And that's what is needed for dither 
>>> effectiveness.   If you're creating noise for dither, you have the option 
>>> to verify its properties.  But in the situation of an analog signal with 
>>> added, independent instrument noise, you do need to verify that the 
>>> composite noise source actually satisfies the criteria for dither.  1/f 
>>> noise in particular has been questioned, which is why I raised the spectrum 
>>> issue.
>>> 
>>> Beyond that, Nigel raises this issue in the context of "self-dither".  In 
>>> situations where there is a clear external noise source present, whether 
>>> the situation is analog to digital conversion or digital to digital bit 
>>> depth change, the external noise may, or may not, be satisfactory as dither 
>>> but at least it's properties can be measured.  If the 'self-dithering' 
>>> instead refers to analog noise captured into the digitized signal with the 
>>> idea that this noise is going to be preserved and available at later 
>>> truncation steps to 'self dither' it is a very very hazy argument.   I'm 
>>> aware of the various caveats that are often postulated, i.e. signal is 
>>> captured at double precision, no truncation, very selected processing.  But 
>>> even in minimalist recording such as live to two track, it's not clear to 
>>> me that the signal can get through the digital stages of the A/D and still 
>>> retain an unaltered noise distribution.  It certainly won't do so after 
>>> considerable processing.  So the sho
> r
>> t
>>> answer is, dither!  At the 24th bit or at the 16th bit, whatever your 
>>> output is.  If you (Nigel or RBJ) have references to the contrary, please 
>>> say so.
>>> 
>>> Vicki
>>> 
>>> On Feb 8, 2015, at 10:11 AM, robert bristow-johnson wrote:
>>> 
 On 2/7/15 8:54 AM, Vicki Melchior wrote:
> Well, the point of dither is to reduce correlation between the signal and 
> quantization noise.  Its effectiveness requires that the error signal has 
> given properties; the mean error should be zero and the RMS error should 
> be independent of the signal.  The best known examples satisfying those 
> conditions are white Gaussian noise at ~ 6dB above the RMS quantization 
> level and white TPDF noise  at ~3dB above the same, with Gaussian noise 
> eliminating correlation entirely and TPDF dither eliminating correlation 
> with the first two moments of the error distribution.   That's all 
> textbook stuff.  There are certainly noise shaping algorithms that shape 
> either the sum of white dither and quantization noise or the white dither 
> and quantization noise independently, and even (to my knowledge) a few 
> completely non-white dithers that are known to work, but determining the 
> effectiveness of noise at dithering still requires examining the 
> statistical properties of the error signal and showi
> n
>> g
>>> 
 th
> at the mean is 0 and the second moment is signal independent.  (I think 
> Stanley Lipschitz showed that the higher moments don't matter to 
> audibility.)
 
 but my question was not about the p.d.f. of the dither (to decouple both 
 the mean and the variance of the quantization error, you need triangular 
 p.d.f. dith

Re: [music-dsp] Dither video and articles

OK, I don’t want to diverge too much from the practical to the theoretical, so 
I’m going to run down what is usual, not what is possible, because it narrows 
the field of discussion.

Most people I know are using recording systems that bussing audio at 32-bit 
float, minimum, and use 64-bit float calculations in plug-ins and significant 
processing. They may still be using 24-bit audio tracks on disk, but for the 
most part they are recorded and are dithered one way or another (primarily 
gaussian noise in the recording process). They may bounce things to tracks to 
free processor cycles. I think in large majority of cases, these are 
self-dithered, but even if it doesn’t happen for some, I don’t think it will 
impact the audio. And if people are worried about it, I don’t understand why 
they aren’t using 32-bit float files, as I think most people have that choices 
these days.

Some of the more hard core will send audio out to a convertor (therefore 
truncated at 24-bit), and back in. Again, I think the vast majority of cases, 
these will self dither, but then there’s the fact error is at a very low level, 
will get buried in the thermal noise of the electronics, etc.

Maybe I left out some other good ones, but to cut it short, yes, I’m mainly 
talking about final mixes. At 24-bit, that often goes to someone else to 
master. The funny thing is that some mastering engineers say “only dither 
once!”, and they want to be the one doing it. Others point out that they may 
want to mess with the dynamic range and boost frequencies, and any error from 
not dithering 24-bit will show up in…you know, the stereo imaging, depth, etc. 
I think it would be exceptional to actually have truncation distortion of 
significant duration, except for potential situations with unusual fades, so 
I’m not worried about saying don’t dither 24-bit, even heading to a mastering 
engineer (but again, do it if you want, it’s just no big deal for final 
outputs–in contrast to the pain in the rear it is to do it at every point for 
the items I mentioned in previous paragraphs).

Down the more theoretical paths, I’ve had people argue that this is a big deal 
because things like ProTools 56k plug-ins need to be dithered internally…but 
why argue legacy stuff that “is what it is”, and secondly, these people usually 
don’t think through how many 24-bit truncations occur in a 56k algorithm, and 
you only have so many cycles. The other thing I sometimes get is the specter of 
the cumulative effect (but what if you have so many tracks, and feedback, 
and…)—but it seems to me that the more of this you get going on, to approach a 
meaningful error magnitude, the more it’s jumbled up in chaos and the less easy 
it is for your ear to recognize it as “bad”.

> On Feb 9, 2015, at 7:54 AM, Vicki Melchior  wrote:
> 
> Nigel, I looked at your video again and it seems to me it's confusing as to 
> whether you mean 'don't dither the 24b final output' or 'don't ever dither at 
> 24b'.  You make statements several times that imply the former, but in your 
> discussion about 24b on all digital interfaces, sends and receives etc, you 
> clearly say to never dither at 24b.  Several people in this thread have 
> pointed out the difference between intermediate stage truncation and final 
> stage truncation, and the fact that if truncation is done repeatedly, any 
> distortion spectra will continue to build.   It is not noise-like, the peaks 
> are coherent peaks and correlated to the signal.  
> 
> You don't say in the video what the processing history is for the files you 
> are using.  If they are simple captures with no processing, they probably 
> reflect the additive gaussian noise present at  the 20th bit in the A/D, 
> based on Andy's post, and are properly dithered for 24b truncation.   My 
> point is that at the digital capture stage you have (S+N) and the amplitude 
> distribution of the S+N signal might be fine for 24b truncation if N is 
> dither-like.  After various stages of digital processing including non-linear 
> steps, the (S+N) intermediate signal may no longer have an adequate amplitude 
> distribution to be truncated without 24b dither.  
> 
> I think the whole subject of self dither might be better approached through 
> FFT measurement than by listening.   Bob Katz shows an FFT of truncation 
> spectra at 24b in his book on 'Itunes Music, Mastering for High Resolution 
> Audio Delivery'  but he uses a generated, dithered pure tone that doesn't 
> start with added gaussian noise.  Haven't thought about it but I can imagine 
> extending his approach into a research effort.  
> 
> Offhand I don't know anything that would go wrong in your difference file (" 
> ...if the error doesn't sound wrong).  It's a common method for looking at 
> residuals.
> 
> Vicki
> 
> 
> On Feb 8, 2015, at 6:11 PM, Nigel Redmon wrote:
> 
>>> Beyond that, Nigel raises this issue in the context of "self-dither”...
>> 
>> First, remember that I’m the guy who recomm

Re: [music-dsp] Dither video and articles

2015-02-09 Thread Vicki Melchior

Nigel, I looked at your video again and it seems to me it's confusing as to 
whether you mean 'don't dither the 24b final output' or 'don't ever dither at 
24b'.  You make statements several times that imply the former, but in your 
discussion about 24b on all digital interfaces, sends and receives etc, you 
clearly say to never dither at 24b.  Several people in this thread have pointed 
out the difference between intermediate stage truncation and final stage 
truncation, and the fact that if truncation is done repeatedly, any distortion 
spectra will continue to build.   It is not noise-like, the peaks are coherent 
peaks and correlated to the signal.  

You don't say in the video what the processing history is for the files you are 
using.  If they are simple captures with no processing, they probably reflect 
the additive gaussian noise present at  the 20th bit in the A/D, based on 
Andy's post, and are properly dithered for 24b truncation.   My point is that 
at the digital capture stage you have (S+N) and the amplitude distribution of 
the S+N signal might be fine for 24b truncation if N is dither-like.  After 
various stages of digital processing including non-linear steps, the (S+N) 
intermediate signal may no longer have an adequate amplitude distribution to be 
truncated without 24b dither.  

I think the whole subject of self dither might be better approached through FFT 
measurement than by listening.   Bob Katz shows an FFT of truncation spectra at 
24b in his book on 'Itunes Music, Mastering for High Resolution Audio Delivery' 
 but he uses a generated, dithered pure tone that doesn't start with added 
gaussian noise.  Haven't thought about it but I can imagine extending his 
approach into a research effort.  

Offhand I don't know anything that would go wrong in your difference file (" 
...if the error doesn't sound wrong).  It's a common method for looking at 
residuals.

Vicki

On Feb 8, 2015, at 6:11 PM, Nigel Redmon wrote:

>> Beyond that, Nigel raises this issue in the context of "self-dither”...
> 
> First, remember that I’m the guy who recommended “always” dithering 16-bit 
> (no “always” as in “alway necessary”, but as in “do it always, unless you 
> know that it gives no improvement”), and to not bother dithering 24-bit. So, 
> I’m only interested in this discussion for 24-bit. That said:
> 
>> ...In situations where there is a clear external noise source present, 
>> whether the situation is analog to digital conversion or digital to digital 
>> bit depth change, the external noise may, or may not, be satisfactory as 
>> dither but at least it's properties can be measured.
> 
> For 24-bit audio, could you give an example of when it’s likely to not be 
> satisfactory (maybe you’ve already given a reference to determining 
> “satisfactory")? Offhand, I’d say one case might be with extremely low noise, 
> then digitally faded such that you fade the noise level below the dithering 
> threshold while you still have enough signal to exhibit truncation 
> distortion, and the fade characteristics allow it to last long enough to 
> matter to your ears—if we weren’t talking about this distortion being down 
> near -140 dB in the first place. I’d think that, typically, you’d have 
> gaussian noise at a much higher level that is needed to dither 24-bit; that 
> could change with digital processing, but I think that in the usual recording 
> chain, it seems pretty hard to avoid for your "analog to digital conversion” 
> case.
> 
> I’m still interested in what you have to say about my post yesterday (“...if 
> the error doesn’t sound wrong to the ear, can it still sound wrong added to 
> the music?”). Care to comment?
> 
> 
>> On Feb 8, 2015, at 8:09 AM, Vicki Melchior  wrote:
>> 
>> I have no argument at all with the cheap high-pass TPDF dither; whenever it 
>> was published the original authors undoubtedly verified that the moment 
>> decoupling occurred, as you say.  And that's what is needed for dither 
>> effectiveness.   If you're creating noise for dither, you have the option to 
>> verify its properties.  But in the situation of an analog signal with added, 
>> independent instrument noise, you do need to verify that the composite noise 
>> source actually satisfies the criteria for dither.  1/f noise in particular 
>> has been questioned, which is why I raised the spectrum issue.  
>> 
>> Beyond that, Nigel raises this issue in the context of "self-dither".  In 
>> situations where there is a clear external noise source present, whether the 
>> situation is analog to digital conversion or digital to digital bit depth 
>> change, the external noise may, or may not, be satisfactory as dither but at 
>> least it's properties can be measured.  If the 'self-dithering' instead 
>> refers to analog noise captured into the digitized signal with the idea that 
>> this noise is going to be preserved and available at later truncation steps 
>> to 'self dither' it is a very very hazy argument.   I'

Re: [music-dsp] Dither video and articles

2015-02-09 Thread Vicki Melchior

That's a clear explanation of the self-dither assumed in A/D conversion, thanks 
for posting it. 

Vicki
 
On Feb 8, 2015, at 9:11 PM, Andrew Simper wrote:

> Vicki,
> 
> If you look at the limits of what is possible in a real world ADC
> there is a certain amount of noise in any electrical system due to
> gaussian thermal noise:
> http://en.wikipedia.org/wiki/Johnson%E2%80%93Nyquist_noise
> 
> For example if you look at an instrument / measurement grade ADC like
> this: 
> http://www.prismsound.com/test_measure/products_subs/dscope/dscope_spec.php
> They publish figures of a residual noise floor of 1.4 uV, which they
> say is -115 dBu. So if you digitise a 1 V peak (2 V peak to peak) sine
> wave with a 24-bit ADC then you will have hiss (which includes a large
> portion of gaussian noise) at around the 20 bit mark, so you will have
> 4-bits of hiss to self dither. This has nothing to do with microphones
> or noise in air, this is in the near perfect case of transmission via
> a well shielded differential cable transferring the voltage directly
> to the ADC.
> 
> All the best,
> 
> Andy
> -- cytomic -- sound music software --
> 
> 
> On 9 February 2015 at 00:09, Vicki Melchior  wrote:
>> I have no argument at all with the cheap high-pass TPDF dither; whenever it 
>> was published the original authors undoubtedly verified that the moment 
>> decoupling occurred, as you say.  And that's what is needed for dither 
>> effectiveness.   If you're creating noise for dither, you have the option to 
>> verify its properties.  But in the situation of an analog signal with added, 
>> independent instrument noise, you do need to verify that the composite noise 
>> source actually satisfies the criteria for dither.  1/f noise in particular 
>> has been questioned, which is why I raised the spectrum issue.
>> 
>> Beyond that, Nigel raises this issue in the context of "self-dither".  In 
>> situations where there is a clear external noise source present, whether the 
>> situation is analog to digital conversion or digital to digital bit depth 
>> change, the external noise may, or may not, be satisfactory as dither but at 
>> least it's properties can be measured.  If the 'self-dithering' instead 
>> refers to analog noise captured into the digitized signal with the idea that 
>> this noise is going to be preserved and available at later truncation steps 
>> to 'self dither' it is a very very hazy argument.   I'm aware of the various 
>> caveats that are often postulated, i.e. signal is captured at double 
>> precision, no truncation, very selected processing.  But even in minimalist 
>> recording such as live to two track, it's not clear to me that the signal 
>> can get through the digital stages of the A/D and still retain an unaltered 
>> noise distribution.  It certainly won't do so after considerable processing. 
>>  So the sho
 r
> t
>> answer is, dither!  At the 24th bit or at the 16th bit, whatever your output 
>> is.  If you (Nigel or RBJ) have references to the contrary, please say so.
>> 
>> Vicki
>> 
>> On Feb 8, 2015, at 10:11 AM, robert bristow-johnson wrote:
>> 
>>> On 2/7/15 8:54 AM, Vicki Melchior wrote:
 Well, the point of dither is to reduce correlation between the signal and 
 quantization noise.  Its effectiveness requires that the error signal has 
 given properties; the mean error should be zero and the RMS error should 
 be independent of the signal.  The best known examples satisfying those 
 conditions are white Gaussian noise at ~ 6dB above the RMS quantization 
 level and white TPDF noise  at ~3dB above the same, with Gaussian noise 
 eliminating correlation entirely and TPDF dither eliminating correlation 
 with the first two moments of the error distribution.   That's all 
 textbook stuff.  There are certainly noise shaping algorithms that shape 
 either the sum of white dither and quantization noise or the white dither 
 and quantization noise independently, and even (to my knowledge) a few 
 completely non-white dithers that are known to work, but determining the 
 effectiveness of noise at dithering still requires examining the 
 statistical properties of the error signal and showi
 n
> g
>> 
>>> th
 at the mean is 0 and the second moment is signal independent.  (I think 
 Stanley Lipschitz showed that the higher moments don't matter to 
 audibility.)
>>> 
>>> but my question was not about the p.d.f. of the dither (to decouple both 
>>> the mean and the variance of the quantization error, you need triangular 
>>> p.d.f. dither of 2 LSBs width that is independent of the *signal*) but 
>>> about the spectrum of the dither.  and Nigel mentioned this already, but 
>>> you can cheaply make high-pass TPDF dither with a single (decent) uniform 
>>> p.d.f. random number per sample and running that through a simple 1st-order 
>>> FIR which has +1 an -1 coefficients (i.e. subtract the previous UPDF from 
>>> the current UPDF to ge

Re: [music-dsp] Dither video and articles

2015-02-08 Thread Andrew Simper

Vicki,

If you look at the limits of what is possible in a real world ADC
there is a certain amount of noise in any electrical system due to
gaussian thermal noise:
http://en.wikipedia.org/wiki/Johnson%E2%80%93Nyquist_noise

For example if you look at an instrument / measurement grade ADC like
this: 
http://www.prismsound.com/test_measure/products_subs/dscope/dscope_spec.php
They publish figures of a residual noise floor of 1.4 uV, which they
say is -115 dBu. So if you digitise a 1 V peak (2 V peak to peak) sine
wave with a 24-bit ADC then you will have hiss (which includes a large
portion of gaussian noise) at around the 20 bit mark, so you will have
4-bits of hiss to self dither. This has nothing to do with microphones
or noise in air, this is in the near perfect case of transmission via
a well shielded differential cable transferring the voltage directly
to the ADC.

All the best,

Andy
-- cytomic -- sound music software --


On 9 February 2015 at 00:09, Vicki Melchior  wrote:
> I have no argument at all with the cheap high-pass TPDF dither; whenever it 
> was published the original authors undoubtedly verified that the moment 
> decoupling occurred, as you say.  And that's what is needed for dither 
> effectiveness.   If you're creating noise for dither, you have the option to 
> verify its properties.  But in the situation of an analog signal with added, 
> independent instrument noise, you do need to verify that the composite noise 
> source actually satisfies the criteria for dither.  1/f noise in particular 
> has been questioned, which is why I raised the spectrum issue.
>
> Beyond that, Nigel raises this issue in the context of "self-dither".  In 
> situations where there is a clear external noise source present, whether the 
> situation is analog to digital conversion or digital to digital bit depth 
> change, the external noise may, or may not, be satisfactory as dither but at 
> least it's properties can be measured.  If the 'self-dithering' instead 
> refers to analog noise captured into the digitized signal with the idea that 
> this noise is going to be preserved and available at later truncation steps 
> to 'self dither' it is a very very hazy argument.   I'm aware of the various 
> caveats that are often postulated, i.e. signal is captured at double 
> precision, no truncation, very selected processing.  But even in minimalist 
> recording such as live to two track, it's not clear to me that the signal can 
> get through the digital stages of the A/D and still retain an unaltered noise 
> distribution.  It certainly won't do so after considerable processing.  So 
> the shor
 t
>  answer is, dither!  At the 24th bit or at the 16th bit, whatever your output 
> is.  If you (Nigel or RBJ) have references to the contrary, please say so.
>
> Vicki
>
> On Feb 8, 2015, at 10:11 AM, robert bristow-johnson wrote:
>
>> On 2/7/15 8:54 AM, Vicki Melchior wrote:
>>> Well, the point of dither is to reduce correlation between the signal and 
>>> quantization noise.  Its effectiveness requires that the error signal has 
>>> given properties; the mean error should be zero and the RMS error should be 
>>> independent of the signal.  The best known examples satisfying those 
>>> conditions are white Gaussian noise at ~ 6dB above the RMS quantization 
>>> level and white TPDF noise  at ~3dB above the same, with Gaussian noise 
>>> eliminating correlation entirely and TPDF dither eliminating correlation 
>>> with the first two moments of the error distribution.   That's all textbook 
>>> stuff.  There are certainly noise shaping algorithms that shape either the 
>>> sum of white dither and quantization noise or the white dither and 
>>> quantization noise independently, and even (to my knowledge) a few 
>>> completely non-white dithers that are known to work, but determining the 
>>> effectiveness of noise at dithering still requires examining the 
>>> statistical properties of the error signal and showin
 g
>
>> th
>>>  at the mean is 0 and the second moment is signal independent.  (I think 
>>> Stanley Lipschitz showed that the higher moments don't matter to 
>>> audibility.)
>>
>> but my question was not about the p.d.f. of the dither (to decouple both the 
>> mean and the variance of the quantization error, you need triangular p.d.f. 
>> dither of 2 LSBs width that is independent of the *signal*) but about the 
>> spectrum of the dither.  and Nigel mentioned this already, but you can 
>> cheaply make high-pass TPDF dither with a single (decent) uniform p.d.f. 
>> random number per sample and running that through a simple 1st-order FIR 
>> which has +1 an -1 coefficients (i.e. subtract the previous UPDF from the 
>> current UPDF to get the high-pass TPDF).  also, i think Bart Locanthi (is he 
>> still on this planet?) and someone else did a simple paper back in the 90s 
>> about the possible benefits of high-pass dither.  wasn't a great paper or 
>> anything, but it was about the same point.
>>
>> i remembe

Re: [music-dsp] Dither video and articles

2015-02-08 Thread Nigel Redmon

>Beyond that, Nigel raises this issue in the context of "self-dither”...

First, remember that I’m the guy who recommended “always” dithering 16-bit (no 
“always” as in “alway necessary”, but as in “do it always, unless you know that 
it gives no improvement”), and to not bother dithering 24-bit. So, I’m only 
interested in this discussion for 24-bit. That said:

>...In situations where there is a clear external noise source present, whether 
>the situation is analog to digital conversion or digital to digital bit depth 
>change, the external noise may, or may not, be satisfactory as dither but at 
>least it's properties can be measured.

For 24-bit audio, could you give an example of when it’s likely to not be 
satisfactory (maybe you’ve already given a reference to determining 
“satisfactory")? Offhand, I’d say one case might be with extremely low noise, 
then digitally faded such that you fade the noise level below the dithering 
threshold while you still have enough signal to exhibit truncation distortion, 
and the fade characteristics allow it to last long enough to matter to your 
ears—if we weren’t talking about this distortion being down near -140 dB in the 
first place. I’d think that, typically, you’d have gaussian noise at a much 
higher level that is needed to dither 24-bit; that could change with digital 
processing, but I think that in the usual recording chain, it seems pretty hard 
to avoid for your "analog to digital conversion” case.

I’m still interested in what you have to say about my post yesterday (“...if 
the error doesn’t sound wrong to the ear, can it still sound wrong added to the 
music?”). Care to comment?


> On Feb 8, 2015, at 8:09 AM, Vicki Melchior  wrote:
> 
> I have no argument at all with the cheap high-pass TPDF dither; whenever it 
> was published the original authors undoubtedly verified that the moment 
> decoupling occurred, as you say.  And that's what is needed for dither 
> effectiveness.   If you're creating noise for dither, you have the option to 
> verify its properties.  But in the situation of an analog signal with added, 
> independent instrument noise, you do need to verify that the composite noise 
> source actually satisfies the criteria for dither.  1/f noise in particular 
> has been questioned, which is why I raised the spectrum issue.  
> 
> Beyond that, Nigel raises this issue in the context of "self-dither".  In 
> situations where there is a clear external noise source present, whether the 
> situation is analog to digital conversion or digital to digital bit depth 
> change, the external noise may, or may not, be satisfactory as dither but at 
> least it's properties can be measured.  If the 'self-dithering' instead 
> refers to analog noise captured into the digitized signal with the idea that 
> this noise is going to be preserved and available at later truncation steps 
> to 'self dither' it is a very very hazy argument.   I'm aware of the various 
> caveats that are often postulated, i.e. signal is captured at double 
> precision, no truncation, very selected processing.  But even in minimalist 
> recording such as live to two track, it's not clear to me that the signal can 
> get through the digital stages of the A/D and still retain an unaltered noise 
> distribution.  It certainly won't do so after considerable processing.  So 
> the short 
> answer is, dither!  At the 24th bit or at the 16th bit, whatever your output 
> is.  If you (Nigel or RBJ) have references to the contrary, please say so.
> 
> Vicki
> 
> On Feb 8, 2015, at 10:11 AM, robert bristow-johnson wrote:
> 
>> On 2/7/15 8:54 AM, Vicki Melchior wrote:
>>> Well, the point of dither is to reduce correlation between the signal and 
>>> quantization noise.  Its effectiveness requires that the error signal has 
>>> given properties; the mean error should be zero and the RMS error should be 
>>> independent of the signal.  The best known examples satisfying those 
>>> conditions are white Gaussian noise at ~ 6dB above the RMS quantization 
>>> level and white TPDF noise  at ~3dB above the same, with Gaussian noise 
>>> eliminating correlation entirely and TPDF dither eliminating correlation 
>>> with the first two moments of the error distribution.   That's all textbook 
>>> stuff.  There are certainly noise shaping algorithms that shape either the 
>>> sum of white dither and quantization noise or the white dither and 
>>> quantization noise independently, and even (to my knowledge) a few 
>>> completely non-white dithers that are known to work, but determining the 
>>> effectiveness of noise at dithering still requires examining the 
>>> statistical properties of the error signal and showing
> 
>> th
>>> at the mean is 0 and the second moment is signal independent.  (I think 
>>> Stanley Lipschitz showed that the higher moments don't matter to 
>>> audibility.)
>> 
>> but my question was not about the p.d.f. of the dither (to decouple both the 
>> mean and the variance of the qua

Re: [music-dsp] Dither video and articles

2015-02-08 Thread Vicki Melchior

I have no argument at all with the cheap high-pass TPDF dither; whenever it was 
published the original authors undoubtedly verified that the moment decoupling 
occurred, as you say.  And that's what is needed for dither effectiveness.   If 
you're creating noise for dither, you have the option to verify its properties. 
 But in the situation of an analog signal with added, independent instrument 
noise, you do need to verify that the composite noise source actually satisfies 
the criteria for dither.  1/f noise in particular has been questioned, which is 
why I raised the spectrum issue.  

Beyond that, Nigel raises this issue in the context of "self-dither".  In 
situations where there is a clear external noise source present, whether the 
situation is analog to digital conversion or digital to digital bit depth 
change, the external noise may, or may not, be satisfactory as dither but at 
least it's properties can be measured.  If the 'self-dithering' instead refers 
to analog noise captured into the digitized signal with the idea that this 
noise is going to be preserved and available at later truncation steps to 'self 
dither' it is a very very hazy argument.   I'm aware of the various caveats 
that are often postulated, i.e. signal is captured at double precision, no 
truncation, very selected processing.  But even in minimalist recording such as 
live to two track, it's not clear to me that the signal can get through the 
digital stages of the A/D and still retain an unaltered noise distribution.  It 
certainly won't do so after considerable processing.  So the short 
 answer is, dither!  At the 24th bit or at the 16th bit, whatever your output 
is.  If you (Nigel or RBJ) have references to the contrary, please say so.

Vicki

On Feb 8, 2015, at 10:11 AM, robert bristow-johnson wrote:

> On 2/7/15 8:54 AM, Vicki Melchior wrote:
>> Well, the point of dither is to reduce correlation between the signal and 
>> quantization noise.  Its effectiveness requires that the error signal has 
>> given properties; the mean error should be zero and the RMS error should be 
>> independent of the signal.  The best known examples satisfying those 
>> conditions are white Gaussian noise at ~ 6dB above the RMS quantization 
>> level and white TPDF noise  at ~3dB above the same, with Gaussian noise 
>> eliminating correlation entirely and TPDF dither eliminating correlation 
>> with the first two moments of the error distribution.   That's all textbook 
>> stuff.  There are certainly noise shaping algorithms that shape either the 
>> sum of white dither and quantization noise or the white dither and 
>> quantization noise independently, and even (to my knowledge) a few 
>> completely non-white dithers that are known to work, but determining the 
>> effectiveness of noise at dithering still requires examining the statistical 
>> properties of the error signal and showing

> th
>>  at the mean is 0 and the second moment is signal independent.  (I think 
>> Stanley Lipschitz showed that the higher moments don't matter to audibility.)
> 
> but my question was not about the p.d.f. of the dither (to decouple both the 
> mean and the variance of the quantization error, you need triangular p.d.f. 
> dither of 2 LSBs width that is independent of the *signal*) but about the 
> spectrum of the dither.  and Nigel mentioned this already, but you can 
> cheaply make high-pass TPDF dither with a single (decent) uniform p.d.f. 
> random number per sample and running that through a simple 1st-order FIR 
> which has +1 an -1 coefficients (i.e. subtract the previous UPDF from the 
> current UPDF to get the high-pass TPDF).  also, i think Bart Locanthi (is he 
> still on this planet?) and someone else did a simple paper back in the 90s 
> about the possible benefits of high-pass dither.  wasn't a great paper or 
> anything, but it was about the same point.
> 
> i remember mentioning this at an AES in the 90's, and Stanley *did* address 
> it.  for straight dither it works okay, but for noise-shaping with feedback, 
> to be perfectly legitimate, you want white TPDF dither (which requires adding 
> or subtracting two independent UPDF random numbers).  and i agree with that.  
> it's just that if someone wanted to make a quick-and-clean high-pass dither 
> with the necessary p.d.f., you can do that with the simple subtraction trick. 
>  and the dither is not white but perfectly decouples the first two moments of 
> the total quantization error.  it's just a simple trick that not good for too 
> much.
> 
> -- 
> 
> r b-j  r...@audioimagination.com
> 
> "Imagination is more important than knowledge."
> 
> 
> 
> 
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews, dsp 
> links
> http://music.columbia.edu/cmc/music-dsp
> http://music.columbia.edu/mailman/listinfo/music-dsp

--
dupswapdrop -- the music-dsp mailing list and website:
subscription

Re: [music-dsp] Dither video and articles

2015-02-08 Thread robert bristow-johnson

On 2/7/15 8:54 AM, Vicki Melchior wrote:
Well, the point of dither is to reduce correlation between the signal and quantization noise. Its effectiveness requires that the error signal has given properties; the mean error should be zero and the RMS error should be independent of the signal. The best known examples satisfying those conditions are white Gaussian noise at ~ 6dB above the RMS quantization level and white TPDF noise at ~3dB above the same, with Gaussian noise eliminating correlation entirely and TPDF dither eliminating correlation with the first two moments of the error distribution. That's all textbook stuff. There are certainly noise shaping algorithms that shape either the sum of white dither and quantization noise or the white dither and quantization noise independently, and even (to my knowledge) a few completely non-white dithers that are known to work, but determining the effectiveness of noise at dithering still requires examining the statistical properties of the error signal and showing

at the mean is 0 and the second moment is signal independent. (I think
Stanley Lipschitz showed that the higher moments don't matter to audibility.)

but my question was not about the p.d.f. of the dither (to decouple both
the mean and the variance of the quantization error, you need triangular
p.d.f. dither of 2 LSBs width that is independent of the *signal*) but
about the spectrum of the dither. and Nigel mentioned this already, but
you can cheaply make high-pass TPDF dither with a single (decent)
uniform p.d.f. random number per sample and running that through a
simple 1st-order FIR which has +1 an -1 coefficients (i.e. subtract the
previous UPDF from the current UPDF to get the high-pass TPDF). also, i
think Bart Locanthi (is he still on this planet?) and someone else did a
simple paper back in the 90s about the possible benefits of high-pass
dither. wasn't a great paper or anything, but it was about the same point.

i remember mentioning this at an AES in the 90's, and Stanley *did*
address it. for straight dither it works okay, but for noise-shaping
with feedback, to be perfectly legitimate, you want white TPDF dither
(which requires adding or subtracting two independent UPDF random
numbers). and i agree with that. it's just that if someone wanted to
make a quick-and-clean high-pass dither with the necessary p.d.f., you
can do that with the simple subtraction trick. and the dither is not
white but perfectly decouples the first two moments of the total
quantization error. it's just a simple trick that not good for too much.

r b-j r...@audioimagination.com

"Imagination is more important than knowledge."

Re: [music-dsp] Dither video and articles

2015-02-07 Thread Nigel Redmon

ng, this was a bit silly a
>>> level, but still definitely not painful to listen to. My point being
>>> that this is a very reasonable test signal to listen to, and it is
>>> clear to hear the differences even at low levels of gain.
>>> 
>>> If I had to choose, between the two 16-bit ones I would prefer the one
>>> with dither but put through a "make mono" plugin, as this sounded the
>>> closest to the float version.
>>> 
>>> All the best,
>>> 
>>> Andy
>>> 
>>> -- cytomic -- sound music software --
>>> 
>>> 
>>> On 5 February 2015 at 16:46, Nigel Redmon  wrote:
>>>> Hmm, I thought that would let you save the page source (wave file)…Safari 
>>>> creates the file of the appropriate name and type, but it stays at 0 
>>>> bytes…OK, I put up and index page—do the usual right-click to save the 
>>>> field to disk if you need to access the files directly:
>>>> 
>>>> http://earlevel.com/temp/music-dsp/
>>>> 
>>>> 
>>>>> On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:
>>>>> 
>>>>> OK, here’s my new piece, I call it Diva bass—to satisfy your request for 
>>>>> me to make something with truncation distortion apparent. (If it bother 
>>>>> you that my piece is one note, imagine that this is just the last note of 
>>>>> a longer piece.)
>>>>> 
>>>>> I spent maybe 30 seconds getting the sound—opened Diva (default 
>>>>> “minimoog” modules), turn the mixer knobs down except for VCO 1, set 
>>>>> range to 32’, waveform to triangle, max release on the VCA envelope.
>>>>> 
>>>>> In 32-bit float glory:
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav
>>>>> 
>>>>> Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), 
>>>>> saved to 16-bit wave file:
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
>>>>> 
>>>>> You’ll have to turn your sound system up, not insanely loud, but loud. (I 
>>>>> said that this would be the case before.) I can hear it, and I know 
>>>>> engineers who monitor much louder, routinely, than I’m monitoring to hear 
>>>>> this. My Equator Q10s are not terribly high powered, and I’m not adding 
>>>>> any other gain ahead of them in order to boost the quiet part.
>>>>> 
>>>>> If you want to hear the residual easily (32-bit version inverted, summed 
>>>>> with 16-bit truncated, the result with +40 dB gain via Trim plug-in):
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav
>>>>> 
>>>>> I don’t expect the 16-bit truncated version to bother you, but it does 
>>>>> bother some audio engineers. Here's 16-bit dithered version, for 
>>>>> completeness, so that you can decide if the added noise floor bothers you:
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav
>>>>> 
>>>>> 
>>>>> 
>>>>>> On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:
>>>>>> 
>>>>>> Yes, I disagree with the "always". "Not always needed" means "it's 
>>>>>> sometimes needed", my point is that it's never needed, until proven 
>>>>>> otherwise. Your video proves that sometimes it's not needed, but not 
>>>>>> that sometimes it's needed.
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> -Message d'origine- From: Nigel Redmon
>>>>>> Sent: Wednesday, February 04, 2015 6:51 PM
>>>>>> To: A discussion list for music-related DSP
>>>>>> Subject: Re: [music-dsp] Dither video and articles
>>>>>> 
>>>>>>> I totally understood the point of your video, that dithering to 16bit 
>>>>>>> isn't always needed - but that's what I disagree with.
>>>>>> 
>>>>>> Sorry, Didier, I’m confused now. I took from your previous message that 
>>>>>> you feel 16-bit doesn’t need to be dithered ("dithering to 16bit will 
>>>>>> never make any audible difference”). Here

Re: [music-dsp] Dither video and articles

2015-02-07 Thread Nigel Redmon

Hi Vicki,

My intuitive view of dither is this (I think you can get this point from my 
video):

After truncation, the error introduced is the truncated signal minus the 
original high resolution signal. We could analyze it statistically, but our 
ears and brain do a real good job of that. And after all, the object here is to 
satisfy our ears and brain.

Listening to the original, high-resolution signal, plus this error signal, is 
equivalent to listening to the truncated signal.

So, my question would be, given such an error signal that sounds smooth, 
pleasant, and unmodulated (hiss-like, not grating, whining, or sputtering, for 
instance): Under what circumstances would the result of adding this error 
signal to the original signal result in an unnecessarily distracting or 
unpleasant degradation of the source material? (And of course, we’re talking 
about 16-bit audio, so not an error of overpowering amplitude.)

I’m not asking this rhetorically, I’d like to know. Measurable statistical 
purity aside, if the error doesn’t sound wrong to the ear, can it still sound 
wrong added to the music? I’ve tried a bit, but so far I haven’t been able to 
convince myself that it can, so I’d appreciate it if someone else could.

Nigel


> On Feb 7, 2015, at 5:54 AM, Vicki Melchior  wrote:
> 
> Hi RBJ,
> 
> Well, the point of dither is to reduce correlation between the signal and 
> quantization noise.  Its effectiveness requires that the error signal has 
> given properties; the mean error should be zero and the RMS error should be 
> independent of the signal.  The best known examples satisfying those 
> conditions are white Gaussian noise at ~ 6dB above the RMS quantization level 
> and white TPDF noise  at ~3dB above the same, with Gaussian noise eliminating 
> correlation entirely and TPDF dither eliminating correlation with the first 
> two moments of the error distribution.   That's all textbook stuff.  There 
> are certainly noise shaping algorithms that shape either the sum of white 
> dither and quantization noise or the white dither and quantization noise 
> independently, and even (to my knowledge) a few completely non-white dithers 
> that are known to work, but determining the effectiveness of noise at 
> dithering still requires examining the statistical properties of the error 
> signal and showing th
> at the mean is 0 and the second moment is signal independent.  (I think 
> Stanley Lipschitz showed that the higher moments don't matter to audibility.)
> 
> Probably there are papers around looking at analog noise in typical music 
> signals and how well it works as self dither (because self dither is assumed 
> in some A/D conversion) but I don't know them and would be very happy to see 
> them.  The one case I know involving some degree of modeling was a tutorial 
> on dither given last year in Berlin that advised against depending on self 
> dither in signal processing unless the noise source was checked out 
> thoroughly before hand.  Variability of amplitude, PDF and time coherence 
> were discussed if I recall.
> 
> Best,
> Vicki 
> 
> On Feb 6, 2015, at 9:27 PM, robert bristow-johnson wrote:
> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>>  Original Message 
>> 
>> Subject: Re: [music-dsp] Dither video and articles
>> 
>> From: "Vicki Melchior" 
>> 
>> Date: Fri, February 6, 2015 2:23 pm
>> 
>> To: "A discussion list for music-related DSP" 
>> 
>> --
>> 
>> 
>> 
>>> The self dither argument is not as obvious as it may appear. To be 
>>> effective at dithering, the noise has to be at the right level of course 
>>> but also should be white and temporally constant.
>> 
>> why does it have to be white?  or why "should" it?
>> 
>> 
>> 
>> 
>> 
>> --
>> 
>> r b-j   r...@audioimagination.com
>> 
>> "Imagination is more important than knowledge."
>> --
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Re: [music-dsp] Dither video and articles

2015-02-07 Thread Nigel Redmon

>why does it have to be white?  or why "should" it?

A common and trivial dither signal for non-shaped dither is rectangular PDF 
noise through a one-pole highpass filter. In other words, instead of generating 
two random numbers and adding them together for the dither signal at each 
sample, one random number is generated, and the random number for the previous 
sample is subtracted. The idea is that it biases the noise toward the highs, 
less in the body of the music, and is a little faster computationally (which 
typically doesn’t mean a thing).

> On Feb 6, 2015, at 6:27 PM, robert bristow-johnson 
>  wrote:
> 
> 
>  Original Message ----
> 
> Subject: Re: [music-dsp] Dither video and articles
> 
> From: "Vicki Melchior" 
> 
> Date: Fri, February 6, 2015 2:23 pm
> 
> To: "A discussion list for music-related DSP" 
> 
> --
> 
> 
>> The self dither argument is not as obvious as it may appear. To be effective 
>> at dithering, the noise has to be at the right level of course but also 
>> should be white and temporally constant.
>  
> why does it have to be white?  or why "should" it?
> 
> 
> --
>  
> r b-j   r...@audioimagination.com
>  
> "Imagination is more important than knowledge."

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Re: [music-dsp] Dither video and articles

2015-02-07 Thread Vicki Melchior

Hi RBJ,

Well, the point of dither is to reduce correlation between the signal and 
quantization noise.  Its effectiveness requires that the error signal has given 
properties; the mean error should be zero and the RMS error should be 
independent of the signal.  The best known examples satisfying those conditions 
are white Gaussian noise at ~ 6dB above the RMS quantization level and white 
TPDF noise  at ~3dB above the same, with Gaussian noise eliminating correlation 
entirely and TPDF dither eliminating correlation with the first two moments of 
the error distribution.   That's all textbook stuff.  There are certainly noise 
shaping algorithms that shape either the sum of white dither and quantization 
noise or the white dither and quantization noise independently, and even (to my 
knowledge) a few completely non-white dithers that are known to work, but 
determining the effectiveness of noise at dithering still requires examining 
the statistical properties of the error signal and showing th
 at the mean is 0 and the second moment is signal independent.  (I think 
Stanley Lipschitz showed that the higher moments don't matter to audibility.)

Probably there are papers around looking at analog noise in typical music 
signals and how well it works as self dither (because self dither is assumed in 
some A/D conversion) but I don't know them and would be very happy to see them. 
 The one case I know involving some degree of modeling was a tutorial on dither 
given last year in Berlin that advised against depending on self dither in 
signal processing unless the noise source was checked out thoroughly before 
hand.  Variability of amplitude, PDF and time coherence were discussed if I 
recall.

Best,
Vicki 

On Feb 6, 2015, at 9:27 PM, robert bristow-johnson wrote:

> 
> 
> 
> 
> 
> 
> 
>  Original Message ------------
> 
> Subject: Re: [music-dsp] Dither video and articles
> 
> From: "Vicki Melchior" 
> 
> Date: Fri, February 6, 2015 2:23 pm
> 
> To: "A discussion list for music-related DSP" 
> 
> --
> 
> 
> 
>> The self dither argument is not as obvious as it may appear. To be effective 
>> at dithering, the noise has to be at the right level of course but also 
>> should be white and temporally constant.
>  
> why does it have to be white?  or why "should" it?
> 
> 
> 
> 
> 
> --
>  
> r b-j   r...@audioimagination.com
>  
> "Imagination is more important than knowledge."
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews, dsp 
> links
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Re: [music-dsp] Dither video and articles

2015-02-07 Thread Andrew Simper

On 7 February 2015 at 03:52, Didier Dambrin  wrote:
> It was just several times the same fading in/out noise at different levels,
> just to see if you hear quieter things than I do, I thought you'd have
> guessed that.
> https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing
> (0dB, -36dB, -54dB, -66dB, -72dB, -78dB)
>
> Here if I make the starting noise annoying, then I hear the first 4 parts,
> until 18:00. Thus, if 0dB is my threshold of annoyance, I can't hear -72dB.
>
> So you hear it at -78dB? Would be interesting to know how many can, and if
> it's subjective or a matter of testing environment (the variable already
> being the 0dB "annoyance" starting point)

Yep, I could hear all of them, and the time I couldn't hear the hiss
any more as at the 28.7 second mark, just before the end of the file.
For reference this noise blast sounded much louder than the bass tone
that Nigel posted when both were normalised, I had my headphones amp
at -18 dB so the first noise peak was loud but not uncomfortable.

I thought it was an odd test since the test file just stopped before I
couldn't hear the LFO amplitude modulation cycles, so I wasn't sure
what you were trying to prove!

All the best,

Andy




> -Message d'origine- From: Andrew Simper
> Sent: Friday, February 06, 2015 3:21 PM
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
>
> Sorry, you said until, which is even more confusing. There are
> multiple points when I hear the noise until since it sounds like the
> noise is modulated in amplitude by a sine like LFO for the entire
> file, so the volume of the noise ramps up and down in a cyclic manner.
> The last ramping I hear fades out at around the 28.7 second mark when
> it is hard to tell if it just ramps out at that point or is just on
> the verge of ramping up again and then the file ends at 28.93 seconds.
> I have not tried to measure the LFO wavelength or any other such
> things, this is just going on listening alone.
>
> All the best,
>
> Andrew Simper
>
>
>
> On 6 February 2015 at 22:01, Andrew Simper  wrote:
>>
>> On 6 February 2015 at 17:32, Didier Dambrin  wrote:
>>>
>>> Just out of curiosity, until which point do you hear the noise in this
>>> little test (a 32bit float wav), starting from a bearable first part?
>>>
>>>
>>> https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing
>>
>>
>> I hear noise immediately in that recording, it's hard to tell exactly
>> the time I can first hear it since there is some latency from when I
>> press play to when the sound starts, but as far as I can tell it is
>> straight away. Why do you ask such silly questions?
>>
>> All the best,
>>
>> Andrew Simper
>
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Re: [music-dsp] Dither video and articles

2015-02-07 Thread Andrew Simper

32-bit internal floating point is not sufficient for certain DSP tasks
and will be plainly audible as causing all sorts of problems, a DF1 at
low frequencies is the classic example of this, it causes large
amounts of low frequency rumble. This is a completely different thing
to the final bit depth of an audio file to listen to.

Andy

-- cytomic -- sound music software --

On 7 February 2015 at 02:24, Michael Gogins  wrote:
>
> Do not believe anything that is not confirmed to a high degree of
> statistical signifance (say, 5 standard deviations) by a double-blind
> test using an ABX comparator.
>
> That said, the AES study did use double-blind testing. I did not read
> the article, only the abstract, so cannot say more about the study.
>
> In my own work, I have verified with a double-blind ABX comparator at
> a high degree of statistical significance that I can hear the
> differences in certain selected portions of the same Csound piece
> rendered with 32 bit floating point samples versus 64 bit floating
> point samples. These are sample words used in internal calculations,
> not for output soundfiles. What I heard was differences in the sound
> of the same filter algorithm. These differences were not at all hard
> to hear, but they occurred in only one or two places in the piece.
>
> I have not myself been able to hear differences in audio output
> quality between CD audio and high-resolution audio, but when I get the
> time I may try again, now that I have a better idea what to listen
> for.
>
> Regards,
> Mike
>
>
>
> -
> Michael Gogins
> Irreducible Productions
> http://michaelgogins.tumblr.com
> Michael dot Gogins at gmail dot com
>
>
> On Fri, Feb 6, 2015 at 1:13 PM, Nigel Redmon  wrote:
> >>Mastering engineers can hear truncation error at the 24th bit but say it is 
> >>subtle and may require experience or training to pick up.
> >
> > Quick observations:
> >
> > 1) The output step size of the lsb is full-scale / 2^24. If full-scale is 
> > 1V, then step is 0.000596046447753906V, or 0.0596 microvolt (millionths 
> > of a volt). Hearing capabilities aside, the converter must be able to 
> > resolve this, and it must make it through the thermal (and other) noise of 
> > their equipment and move a speaker. If you’re not an electrical engineer, 
> > it may be difficult to grasp the problem that this poses.
> >
> > 2) I happened on a discussion in an audio forum, where a highly-acclaimed 
> > mastering engineer and voice on dither mentioned that he could hear the 
> > dither kick in when he pressed a certain button in the GUI of some beta 
> > software. The maker of the software had to inform him that he was mistaken 
> > on the function of the button, and in fact it didn’t affect the audio 
> > whatsoever. (I’ll leave his name out, because it’s immaterial—the guy is a 
> > great source of info to people and is clearly excellent at what he does, 
> > and everyone who works with audio runs into this at some point.) The 
> > mastering engineer graciously accepted his goof.
> >
> > 3) Mastering engineers invariably describe the differences in very 
> > subjective term. While this may be a necessity, it sure makes it difficult 
> > to pursue any kind of validation. From a mastering engineer to me, 
> > yesterday: 'To me the truncated version sounds colder, more glassy, with 
> > less richness in the bass and harmonics, and less "front to back" depth in 
> > the stereo field.’
> >
> > 4) 24-bit audio will almost always have a far greater random noise floor 
> > than is necessary to dither, so they will be self-dithered. By “almost”, I 
> > mean that very near 100% of the time. Sure, you can create exceptions, such 
> > as synthetically generated simple tones, but it’s hard to imagine them 
> > happening in the course of normal music making. There is nothing magic 
> > about dither noise—it’s just mimicking the sort of noise that your 
> > electronics generates thermally. And when mastering engineers say they can 
> > hear truncation distortion at 24-bit, they don’t say “on this particular 
> > brief moment, this particular recording”—they seems to say it in general. 
> > It’s extremely unlikely that non-randomized truncation distortion even 
> > exists for most material at 24-bit.
> >
> > My point is simply that I’m not going to accept that mastering engineers 
> > can hear the 24th bit truncation just because they say they can.
> >
> >
> >> On Feb 6, 2015, at 5:21 AM, Vicki Melchior  wrote:
> >>
> >> The following published double blind test contradicts the results of the 
> >> old Moran/Meyer publication in showing (a) that the differences between CD 
> >> and higher resolution sources is audible and (b) that failure to dither at 
> >> the 16th bit is also audible.
> >>
> >> http://www.aes.org/e-lib/browse.cfm?elib=17497
> >>
> >> The Moran/Meyer tests had numerous technical problems that have long been 
> >> discussed, some are enumerated in the above

Re: [music-dsp] Dither video and articles

2015-02-06 Thread robert bristow-johnson








 Original Message 

Subject: Re: [music-dsp] Dither video and articles

From: "Vicki Melchior" 

Date: Fri, February 6, 2015 2:23 pm

To: "A discussion list for music-related DSP" 

--



> The self dither argument is not as obvious as it may appear. To be effective 
> at dithering, the noise has to be at the right level of course but also 
> should be white and temporally constant.
�
why does it have to be white?� or why "should" it?





--
�
r b-j � � � � � � � � � r...@audioimagination.com
�
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Vicki Melchior

The self dither argument is not as obvious as it may appear.  To be effective 
at dithering, the noise has to be at the right level of course but also should 
be white and temporally constant.  The noise floors present in music data 
normally come from the self noise of the analog components used in recording 
and are composites of a number of noise PDFs.  For example, a graph in a second 
paper by the same group (cited below if wanted) shows spectra of the measured 
noise floors from around a dozen recordings.  The noise spectra are composites 
with the lower frequencies clearly 1/f noise and the upper frequencies summing 
closer to flat.  Whether composite noise of this sort is both temporally 
continuous and white enough to be relied on for dither needs to be shown; it's 
been shown under at least some circumstances (not in these papers) that a 
truncation distortion spectrum can be produced and measured when signals are 
truncated to 24b.  

I'm not saying the self dither argument is necessarily wrong; but it needs 
verification as to when and where it is reliably valid.   If 24b truncation 
turns out to be demonstrably audible in an AB/X, then the self dither idea 
clearly needs to be rethought.

Vicki Melchior

(graph mentioned is fig 8 in this paper:   
http://www.aes.org/e-lib/browse.cfm?elib=17501)

On Feb 6, 2015, at 2:20 PM, Nigel Redmon wrote:

> First, if there is enough noise in the signal before truncation, then it’s 
> dithered by default—no correlation.

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Re: [music-dsp] Dither video and articles

comes then it becomes more obvious aliasing
>>> distortion that everyone is used to hearing.
>>> 
>>> I also tried boosting the float version of the bass tone to -1 dB (so
>>> another 18 dB up from with the same test setup), it was loud, but not
>>> anywhere near the threshold of pain for me. I then boosted it another
>>> 12 dB on the headphone control (so 0 dB gain), so now 30 dB gain in
>>> total and my headphones were really shaking, this was a bit silly a
>>> level, but still definitely not painful to listen to. My point being
>>> that this is a very reasonable test signal to listen to, and it is
>>> clear to hear the differences even at low levels of gain.
>>> 
>>> If I had to choose, between the two 16-bit ones I would prefer the one
>>> with dither but put through a "make mono" plugin, as this sounded the
>>> closest to the float version.
>>> 
>>> All the best,
>>> 
>>> Andy
>>> 
>>> -- cytomic -- sound music software --
>>> 
>>> 
>>> On 5 February 2015 at 16:46, Nigel Redmon  wrote:
>>>> Hmm, I thought that would let you save the page source (wave file)…Safari 
>>>> creates the file of the appropriate name and type, but it stays at 0 
>>>> bytes…OK, I put up and index page—do the usual right-click to save the 
>>>> field to disk if you need to access the files directly:
>>>> 
>>>> http://earlevel.com/temp/music-dsp/
>>>> 
>>>> 
>>>>> On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:
>>>>> 
>>>>> OK, here’s my new piece, I call it Diva bass—to satisfy your request for 
>>>>> me to make something with truncation distortion apparent. (If it bother 
>>>>> you that my piece is one note, imagine that this is just the last note of 
>>>>> a longer piece.)
>>>>> 
>>>>> I spent maybe 30 seconds getting the sound—opened Diva (default 
>>>>> “minimoog” modules), turn the mixer knobs down except for VCO 1, set 
>>>>> range to 32’, waveform to triangle, max release on the VCA envelope.
>>>>> 
>>>>> In 32-bit float glory:
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav
>>>>> 
>>>>> Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), 
>>>>> saved to 16-bit wave file:
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
>>>>> 
>>>>> You’ll have to turn your sound system up, not insanely loud, but loud. (I 
>>>>> said that this would be the case before.) I can hear it, and I know 
>>>>> engineers who monitor much louder, routinely, than I’m monitoring to hear 
>>>>> this. My Equator Q10s are not terribly high powered, and I’m not adding 
>>>>> any other gain ahead of them in order to boost the quiet part.
>>>>> 
>>>>> If you want to hear the residual easily (32-bit version inverted, summed 
>>>>> with 16-bit truncated, the result with +40 dB gain via Trim plug-in):
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav
>>>>> 
>>>>> I don’t expect the 16-bit truncated version to bother you, but it does 
>>>>> bother some audio engineers. Here's 16-bit dithered version, for 
>>>>> completeness, so that you can decide if the added noise floor bothers you:
>>>>> 
>>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav
>>>>> 
>>>>> 
>>>>> 
>>>>>> On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:
>>>>>> 
>>>>>> Yes, I disagree with the "always". "Not always needed" means "it's 
>>>>>> sometimes needed", my point is that it's never needed, until proven 
>>>>>> otherwise. Your video proves that sometimes it's not needed, but not 
>>>>>> that sometimes it's needed.
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> -Message d'origine- From: Nigel Redmon
>>>>>> Sent: Wednesday, February 04, 2015 6:51 PM
>>>>>> To: A discussion list for music-related DSP
>>>>>> Subject: Re: [music-dsp] Dither video and articles
&

Re: [music-dsp] Dither video and articles

I SO agree with 4), that when it comes to recorded & not synthesized (but 
even synthesized in some cases actually - I've made additive synths and it's 
a big CPU saver to avoid processing inaudible partials) audio, room noise is 
so much above the levels we're debating, that it's a bit silly.





-Message d'origine- 
From: Nigel Redmon

Sent: Friday, February 06, 2015 7:13 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Mastering engineers can hear truncation error at the 24th bit but say it is 
subtle and may require experience or training to pick up.


Quick observations:

1) The output step size of the lsb is full-scale / 2^24. If full-scale is 
1V, then step is 0.000596046447753906V, or 0.0596 microvolt (millionths 
of a volt). Hearing capabilities aside, the converter must be able to 
resolve this, and it must make it through the thermal (and other) noise of 
their equipment and move a speaker. If you’re not an electrical engineer, it 
may be difficult to grasp the problem that this poses.


2) I happened on a discussion in an audio forum, where a highly-acclaimed 
mastering engineer and voice on dither mentioned that he could hear the 
dither kick in when he pressed a certain button in the GUI of some beta 
software. The maker of the software had to inform him that he was mistaken 
on the function of the button, and in fact it didn’t affect the audio 
whatsoever. (I’ll leave his name out, because it’s immaterial—the guy is a 
great source of info to people and is clearly excellent at what he does, and 
everyone who works with audio runs into this at some point.) The mastering 
engineer graciously accepted his goof.


3) Mastering engineers invariably describe the differences in very 
subjective term. While this may be a necessity, it sure makes it difficult 
to pursue any kind of validation. From a mastering engineer to me, 
yesterday: 'To me the truncated version sounds colder, more glassy, with 
less richness in the bass and harmonics, and less "front to back" depth in 
the stereo field.’


4) 24-bit audio will almost always have a far greater random noise floor 
than is necessary to dither, so they will be self-dithered. By “almost”, I 
mean that very near 100% of the time. Sure, you can create exceptions, such 
as synthetically generated simple tones, but it’s hard to imagine them 
happening in the course of normal music making. There is nothing magic about 
dither noise—it’s just mimicking the sort of noise that your electronics 
generates thermally. And when mastering engineers say they can hear 
truncation distortion at 24-bit, they don’t say “on this particular brief 
moment, this particular recording”—they seems to say it in general. It’s 
extremely unlikely that non-randomized truncation distortion even exists for 
most material at 24-bit.


My point is simply that I’m not going to accept that mastering engineers can 
hear the 24th bit truncation just because they say they can.



On Feb 6, 2015, at 5:21 AM, Vicki Melchior  
wrote:


The following published double blind test contradicts the results of the 
old Moran/Meyer publication in showing (a) that the differences between CD 
and higher resolution sources is audible and (b) that failure to dither at 
the 16th bit is also audible.


http://www.aes.org/e-lib/browse.cfm?elib=17497

The Moran/Meyer tests had numerous technical problems that have long been 
discussed, some are enumerated in the above.


As far as dithering at the 24th bit, I can't disagree more with a 
conclusion that says it's unnecessary in data handling.  Mastering 
engineers can hear truncation error at the 24th bit but say it is subtle 
and may require experience or training to pick up.  What they are hearing 
is not noise or peaks sitting at the 24th bit but rather the distortion 
that goes with truncation at 24b, and it is said to have a characteristic 
coloration effect on sound.  I'm aware of an effort to show this with AB/X 
tests, hopefully it will be published.  The problem with failing to dither 
at 24b is that many such truncation steps would be done routinely in 
mastering, and thus the truncation distortion products continue to build 
up.  Whether you personally hear it is likely to depend both on how 
extensive your data flow pathway is and how good your playback equipment 
is.


Vicki Melchior

On Feb 5, 2015, at 10:01 PM, Ross Bencina wrote:


On 6/02/2015 1:50 PM, Tom Duffy wrote:

The AES report is highly controversial.

Plenty of sources dispute the findings.


Can you name some?

Ross.
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Re: [music-dsp] Dither video and articles

So you hear all 6 too?

-Message d'origine- 
From: Richard Dobson

Sent: Friday, February 06, 2015 4:10 PM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles

On 06/02/2015 14:21, Andrew Simper wrote:

Sorry, you said until, which is even more confusing. There are
multiple points when I hear the noise until since it sounds like the
noise is modulated in amplitude by a sine like LFO for the entire
file, so the volume of the noise ramps up and down in a cyclic manner.
The last ramping I hear fades out at around the 28.7 second mark when
it is hard to tell if it just ramps out at that point or is just on
the verge of ramping up again and then the file ends at 28.93 seconds.
I have not tried to measure the LFO wavelength or any other such
things, this is just going on listening alone.

Its a series of six smoothly enveloped noise bursts (slowish rise/
slower decay) the first peaking at max amplitude (so you have to be
ready to hear it as very loud!), then successively softer repeats until
at some point it is (presumably?) too quiet to be heard. Very visible in
Audacity using the "Waveform (dB)" display mode. So the word "until" is
entirely appropriate. I do recommend visual inspection of waveforms in
such situations to minimise guessing (or at least, to confirm the
guesses or otherwise). In any case, I would expect people to hear all
six, give a suitably quiet listening environment and an "appropriately
generous" overall playback level etc.

Richard Dobson

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Re: [music-dsp] Dither video and articles

It was just several times the same fading in/out noise at different levels, 
just to see if you hear quieter things than I do, I thought you'd have 
guessed that.

https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing
(0dB, -36dB, -54dB, -66dB, -72dB, -78dB)

Here if I make the starting noise annoying, then I hear the first 4 parts, 
until 18:00. Thus, if 0dB is my threshold of annoyance, I can't hear -72dB.


So you hear it at -78dB? Would be interesting to know how many can, and if 
it's subjective or a matter of testing environment (the variable already 
being the 0dB "annoyance" starting point)





-Message d'origine- 
From: Andrew Simper

Sent: Friday, February 06, 2015 3:21 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Sorry, you said until, which is even more confusing. There are
multiple points when I hear the noise until since it sounds like the
noise is modulated in amplitude by a sine like LFO for the entire
file, so the volume of the noise ramps up and down in a cyclic manner.
The last ramping I hear fades out at around the 28.7 second mark when
it is hard to tell if it just ramps out at that point or is just on
the verge of ramping up again and then the file ends at 28.93 seconds.
I have not tried to measure the LFO wavelength or any other such
things, this is just going on listening alone.

All the best,

Andrew Simper



On 6 February 2015 at 22:01, Andrew Simper  wrote:

On 6 February 2015 at 17:32, Didier Dambrin  wrote:

Just out of curiosity, until which point do you hear the noise in this
little test (a 32bit float wav), starting from a bearable first part?

https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing


I hear noise immediately in that recording, it's hard to tell exactly
the time I can first hear it since there is some latency from when I
press play to when the sound starts, but as far as I can tell it is
straight away. Why do you ask such silly questions?

All the best,

Andrew Simper

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Re: [music-dsp] Dither video and articles


mmh, "Affiliation: Meridian Audio Ltd"?




-Message d'origine- 
From: Vicki Melchior

Sent: Friday, February 06, 2015 2:21 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

The following published double blind test contradicts the results of the old 
Moran/Meyer publication in showing (a) that the differences between CD and 
higher resolution sources is audible and (b) that failure to dither at the 
16th bit is also audible.


http://www.aes.org/e-lib/browse.cfm?elib=17497

The Moran/Meyer tests had numerous technical problems that have long been 
discussed, some are enumerated in the above.


As far as dithering at the 24th bit, I can't disagree more with a conclusion 
that says it's unnecessary in data handling.  Mastering engineers can hear 
truncation error at the 24th bit but say it is subtle and may require 
experience or training to pick up.  What they are hearing is not noise or 
peaks sitting at the 24th bit but rather the distortion that goes with 
truncation at 24b, and it is said to have a characteristic coloration effect 
on sound.  I'm aware of an effort to show this with AB/X tests, hopefully it 
will be published.  The problem with failing to dither at 24b is that many 
such truncation steps would be done routinely in mastering, and thus the 
truncation distortion products continue to build up.  Whether you personally 
hear it is likely to depend both on how extensive your data flow pathway is 
and how good your playback equipment is.


Vicki Melchior

On Feb 5, 2015, at 10:01 PM, Ross Bencina wrote:


On 6/02/2015 1:50 PM, Tom Duffy wrote:

The AES report is highly controversial.

Plenty of sources dispute the findings.


Can you name some?

Ross.
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Re: [music-dsp] Dither video and articles

Hi Michael,

I know that you already understand this, and comment that this is for internal 
calculations, but for the sake of anyone who might misinterpret your 32-bit vs 
64-bit comment, I’ll point out that this is a situation of error feedback—the 
resulting error is much greater than the sample sizes you’re talking about, and 
can result in differences far above the 24-bit level. A simple example is the 
ubiquitous direct form I biquad, which goes all to hell in lower audio 
frequencies with 24-bit storage (unless you noise shape or increase resolution).

Nigel


> On Feb 6, 2015, at 10:24 AM, Michael Gogins  wrote:
> 
> Do not believe anything that is not confirmed to a high degree of
> statistical signifance (say, 5 standard deviations) by a double-blind
> test using an ABX comparator.
> 
> That said, the AES study did use double-blind testing. I did not read
> the article, only the abstract, so cannot say more about the study.
> 
> In my own work, I have verified with a double-blind ABX comparator at
> a high degree of statistical significance that I can hear the
> differences in certain selected portions of the same Csound piece
> rendered with 32 bit floating point samples versus 64 bit floating
> point samples. These are sample words used in internal calculations,
> not for output soundfiles. What I heard was differences in the sound
> of the same filter algorithm. These differences were not at all hard
> to hear, but they occurred in only one or two places in the piece.
> 
> I have not myself been able to hear differences in audio output
> quality between CD audio and high-resolution audio, but when I get the
> time I may try again, now that I have a better idea what to listen
> for.
> 
> Regards,
> Mike
> 
> 
> 
> -
> Michael Gogins
> Irreducible Productions
> http://michaelgogins.tumblr.com
> Michael dot Gogins at gmail dot com
> 
> 
> On Fri, Feb 6, 2015 at 1:13 PM, Nigel Redmon  wrote:
>>> Mastering engineers can hear truncation error at the 24th bit but say it is 
>>> subtle and may require experience or training to pick up.
>> 
>> Quick observations:
>> 
>> 1) The output step size of the lsb is full-scale / 2^24. If full-scale is 
>> 1V, then step is 0.000596046447753906V, or 0.0596 microvolt (millionths 
>> of a volt). Hearing capabilities aside, the converter must be able to 
>> resolve this, and it must make it through the thermal (and other) noise of 
>> their equipment and move a speaker. If you’re not an electrical engineer, it 
>> may be difficult to grasp the problem that this poses.
>> 
>> 2) I happened on a discussion in an audio forum, where a highly-acclaimed 
>> mastering engineer and voice on dither mentioned that he could hear the 
>> dither kick in when he pressed a certain button in the GUI of some beta 
>> software. The maker of the software had to inform him that he was mistaken 
>> on the function of the button, and in fact it didn’t affect the audio 
>> whatsoever. (I’ll leave his name out, because it’s immaterial—the guy is a 
>> great source of info to people and is clearly excellent at what he does, and 
>> everyone who works with audio runs into this at some point.) The mastering 
>> engineer graciously accepted his goof.
>> 
>> 3) Mastering engineers invariably describe the differences in very 
>> subjective term. While this may be a necessity, it sure makes it difficult 
>> to pursue any kind of validation. From a mastering engineer to me, 
>> yesterday: 'To me the truncated version sounds colder, more glassy, with 
>> less richness in the bass and harmonics, and less "front to back" depth in 
>> the stereo field.’
>> 
>> 4) 24-bit audio will almost always have a far greater random noise floor 
>> than is necessary to dither, so they will be self-dithered. By “almost”, I 
>> mean that very near 100% of the time. Sure, you can create exceptions, such 
>> as synthetically generated simple tones, but it’s hard to imagine them 
>> happening in the course of normal music making. There is nothing magic about 
>> dither noise—it’s just mimicking the sort of noise that your electronics 
>> generates thermally. And when mastering engineers say they can hear 
>> truncation distortion at 24-bit, they don’t say “on this particular brief 
>> moment, this particular recording”—they seems to say it in general. It’s 
>> extremely unlikely that non-randomized truncation distortion even exists for 
>> most material at 24-bit.
>> 
>> My point is simply that I’m not going to accept that mastering engineers can 
>> hear the 24th bit truncation just because they say they can.
>> 
>> 
>>> On Feb 6, 2015, at 5:21 AM, Vicki Melchior  wrote:
>>> 
>>> The following published double blind test contradicts the results of the 
>>> old Moran/Meyer publication in showing (a) that the differences between CD 
>>> and higher resolution sources is audible and (b) that failure to dither at 
>>> the 16th bit is also audible.
>>> 
>>> http://www.

Re: [music-dsp] Dither video and articles

>Isn't it generally agreed that truncation noise is correlated with the signal?

“Is correlated”? No, but it can be.

First, if there is enough noise in the signal before truncation, then it’s 
dithered by default—no correlation.

Second, if the signal is sufficiently complex, it seems, then there is no 
apparent correlation. See my video (https://www.youtube.com/watch?v=KCyA6LlB3As 
) where I show a 32-bit float mix, 
truncated to 8-bit, nulled, and boosted +24 dB. There is no apparent 
correlation till the very end, even though the noise floor is not sufficient to 
self-dither.


> On Feb 6, 2015, at 10:42 AM, Tom Duffy  wrote:
> 
> Isn't it generally agreed that truncation noise is correlated with the
> signal?
> The human ear is excellent at picking up on correlation, so a system
> that introduces multiple correlated (noise) signals may reach a point
> where it is perceptual, even if the starting point is a 24 bit signal.
> 
> I would believe this to be an explanation for why ProTools early hardware 
> mixers were regarded as having problems - they used 24bit
> fixed point DSPs, coupled with fixed bit headroom management may
> have introduced truncation noise at a level higher than the 24 bit
> noise floor.
> 
> Also, the dither noise source itself needs to be investigated.
> Studies have shown that a fixed repeated buffer of pre-generated white
> noise is immediately obvious (and non-pleasing) to the listener up to
> several hundred ms long - if that kind of source was used as a dither
> signal, the self correlation becomes even more problematic.
> Calculated a new PRDG value for each sample is expensive, which
> is why a pre-generated buffer is attractive to the implementor.
> 
> ---
> Tom.
> 
> On 2/6/2015 10:32 AM, Victor Lazzarini wrote:
> Quite. This conversation is veering down the vintage wine tasting alley.
> 
> Victor Lazzarini
> Dean of Arts, Celtic Studies, and Philosophy
> Maynooth University
> Ireland
> 
> On 6 Feb 2015, at 18:13, Nigel Redmon  wrote:
> 
> Mastering engineers can hear truncation error at the 24th bit but say it is 
> subtle and may require experience or training to pick up.
> 
> Quick observations:
> 
> 1) The output step size of the lsb is full-scale / 2^24. If full-scale is 1V, 
> then step is 0.000596046447753906V, or 0.0596 microvolt (millionths of a 
> volt). Hearing capabilities aside, the converter must be able to resolve 
> this, and it must make it through the thermal (and other) noise of their 
> equipment and move a speaker. If you’re not an electrical engineer, it may be 
> difficult to grasp the problem that this poses.
> 
> 2) I happened on a discussion in an audio forum, where a highly-acclaimed 
> mastering engineer and voice on dither mentioned that he could hear the 
> dither kick in when he pressed a certain button in the GUI of some beta 
> software. The maker of the software had to inform him that he was mistaken on 
> the function of the button, and in fact it didn’t affect the audio 
> whatsoever. (I’ll leave his name out, because it’s immaterial—the guy is a 
> great source of info to people and is clearly excellent at what he does, and 
> everyone who works with audio runs into this at some point.) The mastering 
> engineer graciously accepted his goof.
> 
> 3) Mastering engineers invariably describe the differences in very subjective 
> term. While this may be a necessity, it sure makes it difficult to pursue any 
> kind of validation. From a mastering engineer to me, yesterday: 'To me the 
> truncated version sounds colder, more glassy, with less richness in the bass 
> and harmonics, and less "front to back" depth in the stereo field.’
> 
> 4) 24-bit audio will almost always have a far greater random noise floor than 
> is necessary to dither, so they will be self-dithered. By “almost”, I mean 
> that very near 100% of the time. Sure, you can create exceptions, such as 
> synthetically generated simple tones, but it’s hard to imagine them happening 
> in the course of normal music making. There is nothing magic about dither 
> noise—it’s just mimicking the sort of noise that your electronics generates 
> thermally. And when mastering engineers say they can hear truncation 
> distortion at 24-bit, they don’t say “on this particular brief moment, this 
> particular recording”—they seems to say it in general. It’s extremely 
> unlikely that non-randomized truncation distortion even exists for most 
> material at 24-bit.
> 
> My point is simply that I’m not going to accept that mastering engineers can 
> hear the 24th bit truncation just because they say they can.
> 
> 
> On Feb 6, 2015, at 5:21 AM, Vicki Melchior  wrote:
> 
> The following published double blind test contradicts the results of the old 
> Moran/Meyer publication in showing (a) that the differences between CD and 
> higher resolution sources is audible and (b) that failure to dither at the 
> 16th bit is also audible.
> 
> http://www.

Re: [music-dsp] Dither video and articles

2015-02-06 Thread Michael Gogins

This was done before John ffitch (I believe it was he) changed the
filter samples in even the single-precision version of Csound to use
double-precision. And I think this change may have been made as a
result of my report.

Regards,
Mike

-
Michael Gogins
Irreducible Productions
http://michaelgogins.tumblr.com
Michael dot Gogins at gmail dot com


On Fri, Feb 6, 2015 at 2:04 PM, Victor Lazzarini
 wrote:
> Yes, but note that in the case Michael is reporting, all filters have 
> double-precision coeffs and data storage. It is only when passing samples 
> between unit generators that the difference lies (either single or
> double precision is used). Still, I believe that
> there can be audible differences.
>
> Victor Lazzarini
> Dean of Arts, Celtic Studies, and Philosophy
> Maynooth University
> Ireland
>
>> On 6 Feb 2015, at 18:43, Ethan Duni  wrote:
>>
>> Thanks for the reference Vicki
>>
>>> What they are hearing is not noise or peaks sitting at the 24th
>>> bit but rather the distortion that goes with truncation at 24b, and
>>> it is said to have a characteristic coloration effect on sound.  I'm
>>> aware of an effort to show this with AB/X tests, hopefully it will be
>> published.
>>
>> I'm skeptical, but definitely hope that such a test gets undertaken and
>> published. Would be interesting to have some real data either way.
>>
>>> The problem with failing to dither at 24b is that many such truncation
>>> steps would be done routinely in mastering, and thus the truncation
>>> distortion products continue to build up.
>>
>> Hopefully everyone agrees that the questions of what is appropriate for
>> intermediate processing and what is appropriate for final distribution are
>> quite different, and that substantially higher resolutions (and probably
>> including dither) are indicated for intermediate processing. As Michael
>> Goggins says:
>>
>>> In my own work, I have verified with a double-blind ABX comparator at
>>> a high degree of statistical significance that I can hear the
>>> differences in certain selected portions of the same Csound piece
>>> rendered with 32 bit floating point samples versus 64 bit floating
>>> point samples. These are sample words used in internal calculations,
>>> not for output soundfiles. What I heard was differences in the sound
>>> of the same filter algorithm. These differences were not at all hard
>>> to hear, but they occurred in only one or two places in the piece.
>>
>> Indeed, it is not particularly difficult to cook up filter
>> designs/algorithms that will break any given finite internal resolution. At
>> some point those filter designs become pathological, but there are plenty
>> of reasonable cases where 32 bit float internal precision is insufficient.
>> Note that a 32-bit float only has 24 bits of mantissa, which is 8 bits less
>> than is typically used in embedded fixed-point implementations (for
>> sensitive components like filter guts, I mean). So even very standard stuff
>> that has been around for decades in the fixed-point world will break if
>> implemented naively in 32 bit float.
>>
>> E
>> --
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Victor Lazzarini

Yes, but note that in the case Michael is reporting, all filters have 
double-precision coeffs and data storage. It is only when passing samples 
between unit generators that the difference lies (either single or
double precision is used). Still, I believe that 
there can be audible differences.

Victor Lazzarini
Dean of Arts, Celtic Studies, and Philosophy
Maynooth University
Ireland

> On 6 Feb 2015, at 18:43, Ethan Duni  wrote:
> 
> Thanks for the reference Vicki
> 
>> What they are hearing is not noise or peaks sitting at the 24th
>> bit but rather the distortion that goes with truncation at 24b, and
>> it is said to have a characteristic coloration effect on sound.  I'm
>> aware of an effort to show this with AB/X tests, hopefully it will be
> published.
> 
> I'm skeptical, but definitely hope that such a test gets undertaken and
> published. Would be interesting to have some real data either way.
> 
>> The problem with failing to dither at 24b is that many such truncation
>> steps would be done routinely in mastering, and thus the truncation
>> distortion products continue to build up.
> 
> Hopefully everyone agrees that the questions of what is appropriate for
> intermediate processing and what is appropriate for final distribution are
> quite different, and that substantially higher resolutions (and probably
> including dither) are indicated for intermediate processing. As Michael
> Goggins says:
> 
>> In my own work, I have verified with a double-blind ABX comparator at
>> a high degree of statistical significance that I can hear the
>> differences in certain selected portions of the same Csound piece
>> rendered with 32 bit floating point samples versus 64 bit floating
>> point samples. These are sample words used in internal calculations,
>> not for output soundfiles. What I heard was differences in the sound
>> of the same filter algorithm. These differences were not at all hard
>> to hear, but they occurred in only one or two places in the piece.
> 
> Indeed, it is not particularly difficult to cook up filter
> designs/algorithms that will break any given finite internal resolution. At
> some point those filter designs become pathological, but there are plenty
> of reasonable cases where 32 bit float internal precision is insufficient.
> Note that a 32-bit float only has 24 bits of mantissa, which is 8 bits less
> than is typically used in embedded fixed-point implementations (for
> sensitive components like filter guts, I mean). So even very standard stuff
> that has been around for decades in the fixed-point world will break if
> implemented naively in 32 bit float.
> 
> E
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews, dsp 
> links
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Ethan Duni

Thanks for the reference Vicki

>What they are hearing is not noise or peaks sitting at the 24th
>bit but rather the distortion that goes with truncation at 24b, and
>it is said to have a characteristic coloration effect on sound.  I'm
>aware of an effort to show this with AB/X tests, hopefully it will be
published.

I'm skeptical, but definitely hope that such a test gets undertaken and
published. Would be interesting to have some real data either way.

>The problem with failing to dither at 24b is that many such truncation
>steps would be done routinely in mastering, and thus the truncation
>distortion products continue to build up.

Hopefully everyone agrees that the questions of what is appropriate for
intermediate processing and what is appropriate for final distribution are
quite different, and that substantially higher resolutions (and probably
including dither) are indicated for intermediate processing. As Michael
Goggins says:

>In my own work, I have verified with a double-blind ABX comparator at
>a high degree of statistical significance that I can hear the
>differences in certain selected portions of the same Csound piece
>rendered with 32 bit floating point samples versus 64 bit floating
>point samples. These are sample words used in internal calculations,
>not for output soundfiles. What I heard was differences in the sound
>of the same filter algorithm. These differences were not at all hard
>to hear, but they occurred in only one or two places in the piece.

Indeed, it is not particularly difficult to cook up filter
designs/algorithms that will break any given finite internal resolution. At
some point those filter designs become pathological, but there are plenty
of reasonable cases where 32 bit float internal precision is insufficient.
Note that a 32-bit float only has 24 bits of mantissa, which is 8 bits less
than is typically used in embedded fixed-point implementations (for
sensitive components like filter guts, I mean). So even very standard stuff
that has been around for decades in the fixed-point world will break if
implemented naively in 32 bit float.

E
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Tom Duffy


Isn't it generally agreed that truncation noise is correlated with the
signal?
The human ear is excellent at picking up on correlation, so a system
that introduces multiple correlated (noise) signals may reach a point
where it is perceptual, even if the starting point is a 24 bit signal.

I would believe this to be an explanation for why ProTools early 
hardware mixers were regarded as having problems - they used 24bit

fixed point DSPs, coupled with fixed bit headroom management may
have introduced truncation noise at a level higher than the 24 bit
noise floor.

Also, the dither noise source itself needs to be investigated.
Studies have shown that a fixed repeated buffer of pre-generated white
noise is immediately obvious (and non-pleasing) to the listener up to
several hundred ms long - if that kind of source was used as a dither
signal, the self correlation becomes even more problematic.
Calculated a new PRDG value for each sample is expensive, which
is why a pre-generated buffer is attractive to the implementor.

---
Tom.

On 2/6/2015 10:32 AM, Victor Lazzarini wrote:
Quite. This conversation is veering down the vintage wine tasting alley.

Victor Lazzarini
Dean of Arts, Celtic Studies, and Philosophy
Maynooth University
Ireland

On 6 Feb 2015, at 18:13, Nigel Redmon  wrote:

Mastering engineers can hear truncation error at the 24th bit but say it 
is subtle and may require experience or training to pick up.


Quick observations:

1) The output step size of the lsb is full-scale / 2^24. If full-scale 
is 1V, then step is 0.000596046447753906V, or 0.0596 microvolt 
(millionths of a volt). Hearing capabilities aside, the converter must 
be able to resolve this, and it must make it through the thermal (and 
other) noise of their equipment and move a speaker. If you’re not an 
electrical engineer, it may be difficult to grasp the problem that this 
poses.


2) I happened on a discussion in an audio forum, where a 
highly-acclaimed mastering engineer and voice on dither mentioned that 
he could hear the dither kick in when he pressed a certain button in the 
GUI of some beta software. The maker of the software had to inform him 
that he was mistaken on the function of the button, and in fact it 
didn’t affect the audio whatsoever. (I’ll leave his name out, because 
it’s immaterial—the guy is a great source of info to people and is 
clearly excellent at what he does, and everyone who works with audio 
runs into this at some point.) The mastering engineer graciously 
accepted his goof.


3) Mastering engineers invariably describe the differences in very 
subjective term. While this may be a necessity, it sure makes it 
difficult to pursue any kind of validation. From a mastering engineer to 
me, yesterday: 'To me the truncated version sounds colder, more glassy, 
with less richness in the bass and harmonics, and less "front to back" 
depth in the stereo field.’


4) 24-bit audio will almost always have a far greater random noise floor 
than is necessary to dither, so they will be self-dithered. By “almost”, 
I mean that very near 100% of the time. Sure, you can create exceptions, 
such as synthetically generated simple tones, but it’s hard to imagine 
them happening in the course of normal music making. There is nothing 
magic about dither noise—it’s just mimicking the sort of noise that your 
electronics generates thermally. And when mastering engineers say they 
can hear truncation distortion at 24-bit, they don’t say “on this 
particular brief moment, this particular recording”—they seems to say it 
in general. It’s extremely unlikely that non-randomized truncation 
distortion even exists for most material at 24-bit.


My point is simply that I’m not going to accept that mastering engineers 
can hear the 24th bit truncation just because they say they can.



On Feb 6, 2015, at 5:21 AM, Vicki Melchior  wrote:

The following published double blind test contradicts the results of the 
old Moran/Meyer publication in showing (a) that the differences between 
CD and higher resolution sources is audible and (b) that failure to 
dither at the 16th bit is also audible.


http://www.aes.org/e-lib/browse.cfm?elib=17497

The Moran/Meyer tests had numerous technical problems that have long 
been discussed, some are enumerated in the above.


As far as dithering at the 24th bit, I can't disagree more with a 
conclusion that says it's unnecessary in data handling.  Mastering 
engineers can hear truncation error at the 24th bit but say it is subtle 
and may require experience or training to pick up.  What they are 
hearing is not noise or peaks sitting at the 24th bit but rather the 
distortion that goes with truncation at 24b, and it is said to have a 
characteristic coloration effect on sound.  I'm aware of an effort to 
show this with AB/X tests, hopefully it will be published.  The problem 
with failing to dither at 24b is that many such truncation steps would 
be done routinely in mastering, and thus the truncat

Re: [music-dsp] Dither video and articles

2015-02-06 Thread Victor Lazzarini

Quite. This conversation is veering down the vintage wine tasting alley.

Victor Lazzarini
Dean of Arts, Celtic Studies, and Philosophy
Maynooth University
Ireland

On 6 Feb 2015, at 18:13, Nigel Redmon  wrote:

>> Mastering engineers can hear truncation error at the 24th bit but say it is 
>> subtle and may require experience or training to pick up.
> 
> Quick observations:
> 
> 1) The output step size of the lsb is full-scale / 2^24. If full-scale is 1V, 
> then step is 0.000596046447753906V, or 0.0596 microvolt (millionths of a 
> volt). Hearing capabilities aside, the converter must be able to resolve 
> this, and it must make it through the thermal (and other) noise of their 
> equipment and move a speaker. If you’re not an electrical engineer, it may be 
> difficult to grasp the problem that this poses.
> 
> 2) I happened on a discussion in an audio forum, where a highly-acclaimed 
> mastering engineer and voice on dither mentioned that he could hear the 
> dither kick in when he pressed a certain button in the GUI of some beta 
> software. The maker of the software had to inform him that he was mistaken on 
> the function of the button, and in fact it didn’t affect the audio 
> whatsoever. (I’ll leave his name out, because it’s immaterial—the guy is a 
> great source of info to people and is clearly excellent at what he does, and 
> everyone who works with audio runs into this at some point.) The mastering 
> engineer graciously accepted his goof.
> 
> 3) Mastering engineers invariably describe the differences in very subjective 
> term. While this may be a necessity, it sure makes it difficult to pursue any 
> kind of validation. From a mastering engineer to me, yesterday: 'To me the 
> truncated version sounds colder, more glassy, with less richness in the bass 
> and harmonics, and less "front to back" depth in the stereo field.’
> 
> 4) 24-bit audio will almost always have a far greater random noise floor than 
> is necessary to dither, so they will be self-dithered. By “almost”, I mean 
> that very near 100% of the time. Sure, you can create exceptions, such as 
> synthetically generated simple tones, but it’s hard to imagine them happening 
> in the course of normal music making. There is nothing magic about dither 
> noise—it’s just mimicking the sort of noise that your electronics generates 
> thermally. And when mastering engineers say they can hear truncation 
> distortion at 24-bit, they don’t say “on this particular brief moment, this 
> particular recording”—they seems to say it in general. It’s extremely 
> unlikely that non-randomized truncation distortion even exists for most 
> material at 24-bit.
> 
> My point is simply that I’m not going to accept that mastering engineers can 
> hear the 24th bit truncation just because they say they can.
> 
> 
>> On Feb 6, 2015, at 5:21 AM, Vicki Melchior  wrote:
>> 
>> The following published double blind test contradicts the results of the old 
>> Moran/Meyer publication in showing (a) that the differences between CD and 
>> higher resolution sources is audible and (b) that failure to dither at the 
>> 16th bit is also audible.  
>> 
>> http://www.aes.org/e-lib/browse.cfm?elib=17497
>> 
>> The Moran/Meyer tests had numerous technical problems that have long been 
>> discussed, some are enumerated in the above.  
>> 
>> As far as dithering at the 24th bit, I can't disagree more with a conclusion 
>> that says it's unnecessary in data handling.  Mastering engineers can hear 
>> truncation error at the 24th bit but say it is subtle and may require 
>> experience or training to pick up.  What they are hearing is not noise or 
>> peaks sitting at the 24th bit but rather the distortion that goes with 
>> truncation at 24b, and it is said to have a characteristic coloration effect 
>> on sound.  I'm aware of an effort to show this with AB/X tests, hopefully it 
>> will be published.  The problem with failing to dither at 24b is that many 
>> such truncation steps would be done routinely in mastering, and thus the 
>> truncation distortion products continue to build up.  Whether you personally 
>> hear it is likely to depend both on how extensive your data flow pathway is 
>> and how good your playback equipment is.  
>> 
>> Vicki Melchior
>> 
>>> On Feb 5, 2015, at 10:01 PM, Ross Bencina wrote:
>>> 
 On 6/02/2015 1:50 PM, Tom Duffy wrote:
 The AES report is highly controversial.
 
 Plenty of sources dispute the findings.
>>> 
>>> Can you name some?
>>> 
>>> Ross.
>>> --
> 
> --
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Michael Gogins

Do not believe anything that is not confirmed to a high degree of
statistical signifance (say, 5 standard deviations) by a double-blind
test using an ABX comparator.

That said, the AES study did use double-blind testing. I did not read
the article, only the abstract, so cannot say more about the study.

In my own work, I have verified with a double-blind ABX comparator at
a high degree of statistical significance that I can hear the
differences in certain selected portions of the same Csound piece
rendered with 32 bit floating point samples versus 64 bit floating
point samples. These are sample words used in internal calculations,
not for output soundfiles. What I heard was differences in the sound
of the same filter algorithm. These differences were not at all hard
to hear, but they occurred in only one or two places in the piece.

I have not myself been able to hear differences in audio output
quality between CD audio and high-resolution audio, but when I get the
time I may try again, now that I have a better idea what to listen
for.

Regards,
Mike



-
Michael Gogins
Irreducible Productions
http://michaelgogins.tumblr.com
Michael dot Gogins at gmail dot com


On Fri, Feb 6, 2015 at 1:13 PM, Nigel Redmon  wrote:
>>Mastering engineers can hear truncation error at the 24th bit but say it is 
>>subtle and may require experience or training to pick up.
>
> Quick observations:
>
> 1) The output step size of the lsb is full-scale / 2^24. If full-scale is 1V, 
> then step is 0.000596046447753906V, or 0.0596 microvolt (millionths of a 
> volt). Hearing capabilities aside, the converter must be able to resolve 
> this, and it must make it through the thermal (and other) noise of their 
> equipment and move a speaker. If you’re not an electrical engineer, it may be 
> difficult to grasp the problem that this poses.
>
> 2) I happened on a discussion in an audio forum, where a highly-acclaimed 
> mastering engineer and voice on dither mentioned that he could hear the 
> dither kick in when he pressed a certain button in the GUI of some beta 
> software. The maker of the software had to inform him that he was mistaken on 
> the function of the button, and in fact it didn’t affect the audio 
> whatsoever. (I’ll leave his name out, because it’s immaterial—the guy is a 
> great source of info to people and is clearly excellent at what he does, and 
> everyone who works with audio runs into this at some point.) The mastering 
> engineer graciously accepted his goof.
>
> 3) Mastering engineers invariably describe the differences in very subjective 
> term. While this may be a necessity, it sure makes it difficult to pursue any 
> kind of validation. From a mastering engineer to me, yesterday: 'To me the 
> truncated version sounds colder, more glassy, with less richness in the bass 
> and harmonics, and less "front to back" depth in the stereo field.’
>
> 4) 24-bit audio will almost always have a far greater random noise floor than 
> is necessary to dither, so they will be self-dithered. By “almost”, I mean 
> that very near 100% of the time. Sure, you can create exceptions, such as 
> synthetically generated simple tones, but it’s hard to imagine them happening 
> in the course of normal music making. There is nothing magic about dither 
> noise—it’s just mimicking the sort of noise that your electronics generates 
> thermally. And when mastering engineers say they can hear truncation 
> distortion at 24-bit, they don’t say “on this particular brief moment, this 
> particular recording”—they seems to say it in general. It’s extremely 
> unlikely that non-randomized truncation distortion even exists for most 
> material at 24-bit.
>
> My point is simply that I’m not going to accept that mastering engineers can 
> hear the 24th bit truncation just because they say they can.
>
>
>> On Feb 6, 2015, at 5:21 AM, Vicki Melchior  wrote:
>>
>> The following published double blind test contradicts the results of the old 
>> Moran/Meyer publication in showing (a) that the differences between CD and 
>> higher resolution sources is audible and (b) that failure to dither at the 
>> 16th bit is also audible.
>>
>> http://www.aes.org/e-lib/browse.cfm?elib=17497
>>
>> The Moran/Meyer tests had numerous technical problems that have long been 
>> discussed, some are enumerated in the above.
>>
>> As far as dithering at the 24th bit, I can't disagree more with a conclusion 
>> that says it's unnecessary in data handling.  Mastering engineers can hear 
>> truncation error at the 24th bit but say it is subtle and may require 
>> experience or training to pick up.  What they are hearing is not noise or 
>> peaks sitting at the 24th bit but rather the distortion that goes with 
>> truncation at 24b, and it is said to have a characteristic coloration effect 
>> on sound.  I'm aware of an effort to show this with AB/X tests, hopefully it 
>> will be published.  The problem with failing to

Re: [music-dsp] Dither video and articles

>Mastering engineers can hear truncation error at the 24th bit but say it is 
>subtle and may require experience or training to pick up.

Quick observations:

1) The output step size of the lsb is full-scale / 2^24. If full-scale is 1V, 
then step is 0.000596046447753906V, or 0.0596 microvolt (millionths of a 
volt). Hearing capabilities aside, the converter must be able to resolve this, 
and it must make it through the thermal (and other) noise of their equipment 
and move a speaker. If you’re not an electrical engineer, it may be difficult 
to grasp the problem that this poses.

2) I happened on a discussion in an audio forum, where a highly-acclaimed 
mastering engineer and voice on dither mentioned that he could hear the dither 
kick in when he pressed a certain button in the GUI of some beta software. The 
maker of the software had to inform him that he was mistaken on the function of 
the button, and in fact it didn’t affect the audio whatsoever. (I’ll leave his 
name out, because it’s immaterial—the guy is a great source of info to people 
and is clearly excellent at what he does, and everyone who works with audio 
runs into this at some point.) The mastering engineer graciously accepted his 
goof.

3) Mastering engineers invariably describe the differences in very subjective 
term. While this may be a necessity, it sure makes it difficult to pursue any 
kind of validation. From a mastering engineer to me, yesterday: 'To me the 
truncated version sounds colder, more glassy, with less richness in the bass 
and harmonics, and less "front to back" depth in the stereo field.’

4) 24-bit audio will almost always have a far greater random noise floor than 
is necessary to dither, so they will be self-dithered. By “almost”, I mean that 
very near 100% of the time. Sure, you can create exceptions, such as 
synthetically generated simple tones, but it’s hard to imagine them happening 
in the course of normal music making. There is nothing magic about dither 
noise—it’s just mimicking the sort of noise that your electronics generates 
thermally. And when mastering engineers say they can hear truncation distortion 
at 24-bit, they don’t say “on this particular brief moment, this particular 
recording”—they seems to say it in general. It’s extremely unlikely that 
non-randomized truncation distortion even exists for most material at 24-bit.

My point is simply that I’m not going to accept that mastering engineers can 
hear the 24th bit truncation just because they say they can.

> On Feb 6, 2015, at 5:21 AM, Vicki Melchior  wrote:
> 
> The following published double blind test contradicts the results of the old 
> Moran/Meyer publication in showing (a) that the differences between CD and 
> higher resolution sources is audible and (b) that failure to dither at the 
> 16th bit is also audible.  
> 
> http://www.aes.org/e-lib/browse.cfm?elib=17497
> 
> The Moran/Meyer tests had numerous technical problems that have long been 
> discussed, some are enumerated in the above.  
> 
> As far as dithering at the 24th bit, I can't disagree more with a conclusion 
> that says it's unnecessary in data handling.  Mastering engineers can hear 
> truncation error at the 24th bit but say it is subtle and may require 
> experience or training to pick up.  What they are hearing is not noise or 
> peaks sitting at the 24th bit but rather the distortion that goes with 
> truncation at 24b, and it is said to have a characteristic coloration effect 
> on sound.  I'm aware of an effort to show this with AB/X tests, hopefully it 
> will be published.  The problem with failing to dither at 24b is that many 
> such truncation steps would be done routinely in mastering, and thus the 
> truncation distortion products continue to build up.  Whether you personally 
> hear it is likely to depend both on how extensive your data flow pathway is 
> and how good your playback equipment is.  
> 
> Vicki Melchior
> 
> On Feb 5, 2015, at 10:01 PM, Ross Bencina wrote:
> 
>> On 6/02/2015 1:50 PM, Tom Duffy wrote:
>>> The AES report is highly controversial.
>>> 
>>> Plenty of sources dispute the findings.
>> 
>> Can you name some?
>> 
>> Ross.
>> --

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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Richard Dobson


On 06/02/2015 14:21, Andrew Simper wrote:

Sorry, you said until, which is even more confusing. There are
multiple points when I hear the noise until since it sounds like the
noise is modulated in amplitude by a sine like LFO for the entire
file, so the volume of the noise ramps up and down in a cyclic manner.
The last ramping I hear fades out at around the 28.7 second mark when
it is hard to tell if it just ramps out at that point or is just on
the verge of ramping up again and then the file ends at 28.93 seconds.
I have not tried to measure the LFO wavelength or any other such
things, this is just going on listening alone.




Its a series of six smoothly enveloped noise bursts (slowish rise/ 
slower decay) the first peaking at max amplitude (so you have to be 
ready to hear it as very loud!), then successively softer repeats until 
at some point it is (presumably?) too quiet to be heard. Very visible in 
Audacity using the "Waveform (dB)" display mode. So the word "until" is 
entirely appropriate. I do recommend visual inspection of waveforms in 
such situations to minimise guessing (or at least, to confirm the 
guesses or otherwise). In any case, I would expect people to hear all 
six, give a suitably quiet listening environment and an "appropriately 
generous" overall playback level etc.


Richard Dobson


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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Andrew Simper

Sorry, you said until, which is even more confusing. There are
multiple points when I hear the noise until since it sounds like the
noise is modulated in amplitude by a sine like LFO for the entire
file, so the volume of the noise ramps up and down in a cyclic manner.
The last ramping I hear fades out at around the 28.7 second mark when
it is hard to tell if it just ramps out at that point or is just on
the verge of ramping up again and then the file ends at 28.93 seconds.
I have not tried to measure the LFO wavelength or any other such
things, this is just going on listening alone.

All the best,

Andrew Simper

On 6 February 2015 at 22:01, Andrew Simper  wrote:
> On 6 February 2015 at 17:32, Didier Dambrin  wrote:
>> Just out of curiosity, until which point do you hear the noise in this
>> little test (a 32bit float wav), starting from a bearable first part?
>>
>> https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing
>
> I hear noise immediately in that recording, it's hard to tell exactly
> the time I can first hear it since there is some latency from when I
> press play to when the sound starts, but as far as I can tell it is
> straight away. Why do you ask such silly questions?
>
> All the best,
>
> Andrew Simper
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Andrew Simper

On 6 February 2015 at 17:32, Didier Dambrin  wrote:
> Just out of curiosity, until which point do you hear the noise in this
> little test (a 32bit float wav), starting from a bearable first part?
>
> https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing

I hear noise immediately in that recording, it's hard to tell exactly
the time I can first hear it since there is some latency from when I
press play to when the sound starts, but as far as I can tell it is
straight away. Why do you ask such silly questions?

All the best,

Andrew Simper
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Vicki Melchior

The following published double blind test contradicts the results of the old 
Moran/Meyer publication in showing (a) that the differences between CD and 
higher resolution sources is audible and (b) that failure to dither at the 16th 
bit is also audible.  

http://www.aes.org/e-lib/browse.cfm?elib=17497

The Moran/Meyer tests had numerous technical problems that have long been 
discussed, some are enumerated in the above.  

As far as dithering at the 24th bit, I can't disagree more with a conclusion 
that says it's unnecessary in data handling.  Mastering engineers can hear 
truncation error at the 24th bit but say it is subtle and may require 
experience or training to pick up.  What they are hearing is not noise or peaks 
sitting at the 24th bit but rather the distortion that goes with truncation at 
24b, and it is said to have a characteristic coloration effect on sound.  I'm 
aware of an effort to show this with AB/X tests, hopefully it will be 
published.  The problem with failing to dither at 24b is that many such 
truncation steps would be done routinely in mastering, and thus the truncation 
distortion products continue to build up.  Whether you personally hear it is 
likely to depend both on how extensive your data flow pathway is and how good 
your playback equipment is.  

Vicki Melchior

On Feb 5, 2015, at 10:01 PM, Ross Bencina wrote:

> On 6/02/2015 1:50 PM, Tom Duffy wrote:
>> The AES report is highly controversial.
>> 
>> Plenty of sources dispute the findings.
> 
> Can you name some?
> 
> Ross.
> --
> dupswapdrop -- the music-dsp mailing list and website:
> subscription info, FAQ, source code archive, list archive, book reviews, dsp 
> links
> http://music.columbia.edu/cmc/music-dsp
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Re: [music-dsp] Dither video and articles

2015-02-06 Thread Ethan Duni

>Here's a double-blind A/B/X test that indicated no
>one could hear the difference between 16 and 24 bit.
>24-bit is better than 16-bit with dithering so maybe
>you can extrapolate.

I'd strongly prefer a direct test. For one thing, it's not clear to me
whether it is possible to extrapolate any conclusions about dither from
those results, for the simple reason that they do not specify whether the
16 bit D/A they used employed dither or not.

Which isn't to say that I disagree with the paper's conclusions about the
appropriateness of 16 bit for consumer distribution. But it doesn't really
speak to the question of dither.

>Wait, are you saying that you would then introduce
>an even greater dithering noise, to mask possible
>dynamic range reduction in the playback chain?

No, I'm simply pointing out a use case where the noise floor of a 16 bit
recording ends up more audible. If you compress the dynamic range in the
playback chain, then spurs that were sitting at -90dB end up louder (for a
given peak volumes). At some point it becomes noticeable, and without
anybody's ears bleeding.

Let me emphasize that I agree with the general consensus that dither for 16
bit is worthwhile, but not necessarily noticeable on most recordings or
playback systems. It's kind of the boundary of where dither is still
generally indicated, at higher resolutions it becomes silly.

E
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Re: [music-dsp] Dither video and articles

Just out of curiosity, until which point do you hear the noise in this 
little test (a 32bit float wav), starting from a bearable first part?


https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing




-Message d'origine- 
From: Andrew Simper

Sent: Friday, February 06, 2015 8:21 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

On 6 February 2015 at 12:16, Didier Dambrin  wrote:

I'm not quite sure I understand what you described here below.
I think the wavs should have contained a normalized part, so that anyone 
who
listens to it, will never crank up his volume above the threshold of pain 
on

the first, normalized part, and then everyone is more or less listening to
the quiet part the same way.


That is exactly what I was doing, to normalise the float wav file and
let you know it wasn't even remotely near the level of pain, which
tells me the gain of -12 dB on the headphone amp is a reasonable
listening level.



Claiming that it's any audible is one thing, but you go as far as saying
it's clear to hear.. we're probably not testing the same way.
I have normalized (+23dB) the last 9 seconds of the Diva bass 16-bit
truncated.wav file to hear what I was supposed to hear. I'm just not 
hearing

anything close to that, in the normal test.


I can only say what I hear, which is pretty clear. Nigel's point about
the volume is this: at one point in the song that bass sound would be
normalised up higher, or perhaps behind drums which were louder, but
you can consider this bit as being in a quieter bit of a song, so
absolutely reasonable as a test case.



While I have Sennheiser HD650, I'm listening through bose QC15 because,
although it's night time, my ambient noise is probably a gazillion times
above what we're debating here. So I'm in a pretty quiet listening setup
here (for those who have tried QC15's).


If you can't hear it I believe you, but I can hear it. Not all peoples
hearing is equal.

All the best,

Andrew Simper






-Message d'origine- From: Andrew Simper
Sent: Friday, February 06, 2015 3:31 AM

To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

I also tried boosting the float version of the bass tone to -1 dB (so
another 18 dB up from with the same test setup), it was loud, but not
anywhere near the threshold of pain for me. I then boosted it another
12 dB on the headphone control (so 0 dB gain), so now 30 dB gain in
total and my headphones were really shaking, this was a bit silly a
level, but still definitely not painful to listen to. My point being
that this is a very reasonable test signal to listen to, and it is
clear to hear the differences even at low levels of gain.

If I had to choose, between the two 16-bit ones I would prefer the one
with dither but put through a "make mono" plugin, as this sounded the
closest to the float version.

All the best,

Andy

-- cytomic -- sound music software --


On 5 February 2015 at 16:46, Nigel Redmon  wrote:


Hmm, I thought that would let you save the page source (wave file)…Safari
creates the file of the appropriate name and type, but it stays at 0
bytes…OK, I put up and index page—do the usual right-click to save the 
field

to disk if you need to access the files directly:

http://earlevel.com/temp/music-dsp/



On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:

OK, here’s my new piece, I call it Diva bass—to satisfy your request for
me to make something with truncation distortion apparent. (If it bother 
you

that my piece is one note, imagine that this is just the last note of a
longer piece.)

I spent maybe 30 seconds getting the sound—opened Diva (default
“minimoog” modules), turn the mixer knobs down except for VCO 1, set 
range

to 32’, waveform to triangle, max release on the VCA envelope.

In 32-bit float glory:

http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav

Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer),
saved to 16-bit wave file:

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav

You’ll have to turn your sound system up, not insanely loud, but loud. 
(I

said that this would be the case before.) I can hear it, and I know
engineers who monitor much louder, routinely, than I’m monitoring to 
hear
this. My Equator Q10s are not terribly high powered, and I’m not adding 
any

other gain ahead of them in order to boost the quiet part.

If you want to hear the residual easily (32-bit version inverted, summed
with 16-bit truncated, the result with +40 dB gain via Trim plug-in):


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav

I don’t expect the 16-bit truncated version to bother you, but it does
bother some audio engineers. Here's 16-bit dithered version, for
completeness, so that you can decide if the

Re: [music-dsp] Dither video and articles

urce (wave file)…Safari 
>>> creates the file of the appropriate name and type, but it stays at 0 
>>> bytes…OK, I put up and index page—do the usual right-click to save the 
>>> field to disk if you need to access the files directly:
>>>
>>> http://earlevel.com/temp/music-dsp/
>>>
>>>
>>>> On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:
>>>>
>>>> OK, here’s my new piece, I call it Diva bass—to satisfy your request for 
>>>> me to make something with truncation distortion apparent. (If it bother 
>>>> you that my piece is one note, imagine that this is just the last note of 
>>>> a longer piece.)
>>>>
>>>> I spent maybe 30 seconds getting the sound—opened Diva (default “minimoog” 
>>>> modules), turn the mixer knobs down except for VCO 1, set range to 32’, 
>>>> waveform to triangle, max release on the VCA envelope.
>>>>
>>>> In 32-bit float glory:
>>>>
>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav
>>>>
>>>> Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), saved 
>>>> to 16-bit wave file:
>>>>
>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
>>>>
>>>> You’ll have to turn your sound system up, not insanely loud, but loud. (I 
>>>> said that this would be the case before.) I can hear it, and I know 
>>>> engineers who monitor much louder, routinely, than I’m monitoring to hear 
>>>> this. My Equator Q10s are not terribly high powered, and I’m not adding 
>>>> any other gain ahead of them in order to boost the quiet part.
>>>>
>>>> If you want to hear the residual easily (32-bit version inverted, summed 
>>>> with 16-bit truncated, the result with +40 dB gain via Trim plug-in):
>>>>
>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav
>>>>
>>>> I don’t expect the 16-bit truncated version to bother you, but it does 
>>>> bother some audio engineers. Here's 16-bit dithered version, for 
>>>> completeness, so that you can decide if the added noise floor bothers you:
>>>>
>>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav
>>>>
>>>>
>>>>
>>>>> On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:
>>>>>
>>>>> Yes, I disagree with the "always". "Not always needed" means "it's 
>>>>> sometimes needed", my point is that it's never needed, until proven 
>>>>> otherwise. Your video proves that sometimes it's not needed, but not that 
>>>>> sometimes it's needed.
>>>>>
>>>>>
>>>>>
>>>>> -Message d'origine- From: Nigel Redmon
>>>>> Sent: Wednesday, February 04, 2015 6:51 PM
>>>>> To: A discussion list for music-related DSP
>>>>> Subject: Re: [music-dsp] Dither video and articles
>>>>>
>>>>>> I totally understood the point of your video, that dithering to 16bit 
>>>>>> isn't always needed - but that's what I disagree with.
>>>>>
>>>>> Sorry, Didier, I’m confused now. I took from your previous message that 
>>>>> you feel 16-bit doesn’t need to be dithered ("dithering to 16bit will 
>>>>> never make any audible difference”). Here you say that you disagree with 
>>>>> "dithering to 16bit isn't always needed”. In fact, you are saying that 
>>>>> it’s never needed—you disagree because “isn’t always needed” implies that 
>>>>> it is sometimes needed—correct?
>>>>>
>>>>>
>>>>>> On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:
>>>>>>
>>>>>>>> Then, it’s no-win situation, because I could EASILY manufacture a bit 
>>>>>>>> of music that had significant truncation distortion at 16-bit.
>>>>>>
>>>>>> Please do, I would really like to hear it.
>>>>>>
>>>>>> I have never heard truncation noise at 16bit, other than by playing with 
>>>>>> levels in a such a way that the peaking parts of the rest of the sound 
>>>>>> would destroy your ears or be very unpleasant at best. (you say 12dB, 
>>>>>> it's

Re: [music-dsp] Dither video and articles

On 6 February 2015 at 12:16, Didier Dambrin  wrote:
> I'm not quite sure I understand what you described here below.
> I think the wavs should have contained a normalized part, so that anyone who
> listens to it, will never crank up his volume above the threshold of pain on
> the first, normalized part, and then everyone is more or less listening to
> the quiet part the same way.

That is exactly what I was doing, to normalise the float wav file and
let you know it wasn't even remotely near the level of pain, which
tells me the gain of -12 dB on the headphone amp is a reasonable
listening level.


> Claiming that it's any audible is one thing, but you go as far as saying
> it's clear to hear.. we're probably not testing the same way.
> I have normalized (+23dB) the last 9 seconds of the Diva bass 16-bit
> truncated.wav file to hear what I was supposed to hear. I'm just not hearing
> anything close to that, in the normal test.

I can only say what I hear, which is pretty clear. Nigel's point about
the volume is this: at one point in the song that bass sound would be
normalised up higher, or perhaps behind drums which were louder, but
you can consider this bit as being in a quieter bit of a song, so
absolutely reasonable as a test case.


> While I have Sennheiser HD650, I'm listening through bose QC15 because,
> although it's night time, my ambient noise is probably a gazillion times
> above what we're debating here. So I'm in a pretty quiet listening setup
> here (for those who have tried QC15's).

If you can't hear it I believe you, but I can hear it. Not all peoples
hearing is equal.

All the best,

Andrew Simper


>
>
>
> -Message d'origine- From: Andrew Simper
> Sent: Friday, February 06, 2015 3:31 AM
>
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
>
> I also tried boosting the float version of the bass tone to -1 dB (so
> another 18 dB up from with the same test setup), it was loud, but not
> anywhere near the threshold of pain for me. I then boosted it another
> 12 dB on the headphone control (so 0 dB gain), so now 30 dB gain in
> total and my headphones were really shaking, this was a bit silly a
> level, but still definitely not painful to listen to. My point being
> that this is a very reasonable test signal to listen to, and it is
> clear to hear the differences even at low levels of gain.
>
> If I had to choose, between the two 16-bit ones I would prefer the one
> with dither but put through a "make mono" plugin, as this sounded the
> closest to the float version.
>
> All the best,
>
> Andy
>
> -- cytomic -- sound music software --
>
>
> On 5 February 2015 at 16:46, Nigel Redmon  wrote:
>>
>> Hmm, I thought that would let you save the page source (wave file)…Safari
>> creates the file of the appropriate name and type, but it stays at 0
>> bytes…OK, I put up and index page—do the usual right-click to save the field
>> to disk if you need to access the files directly:
>>
>> http://earlevel.com/temp/music-dsp/
>>
>>
>>> On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:
>>>
>>> OK, here’s my new piece, I call it Diva bass—to satisfy your request for
>>> me to make something with truncation distortion apparent. (If it bother you
>>> that my piece is one note, imagine that this is just the last note of a
>>> longer piece.)
>>>
>>> I spent maybe 30 seconds getting the sound—opened Diva (default
>>> “minimoog” modules), turn the mixer knobs down except for VCO 1, set range
>>> to 32’, waveform to triangle, max release on the VCA envelope.
>>>
>>> In 32-bit float glory:
>>>
>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav
>>>
>>> Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer),
>>> saved to 16-bit wave file:
>>>
>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
>>>
>>> You’ll have to turn your sound system up, not insanely loud, but loud. (I
>>> said that this would be the case before.) I can hear it, and I know
>>> engineers who monitor much louder, routinely, than I’m monitoring to hear
>>> this. My Equator Q10s are not terribly high powered, and I’m not adding any
>>> other gain ahead of them in order to boost the quiet part.
>>>
>>> If you want to hear the residual easily (32-bit version inverted, summed
>>> with 16-bit truncated, the result with +40 dB gain via Trim plug-in):
>>>
>>>
>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2

Re: [music-dsp] Dither video and articles

16-bit, no dither (Quan Jr plug-in, Digital Performer), saved 
>>> to 16-bit wave file:
>>> 
>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
>>> 
>>> You’ll have to turn your sound system up, not insanely loud, but loud. (I 
>>> said that this would be the case before.) I can hear it, and I know 
>>> engineers who monitor much louder, routinely, than I’m monitoring to hear 
>>> this. My Equator Q10s are not terribly high powered, and I’m not adding any 
>>> other gain ahead of them in order to boost the quiet part.
>>> 
>>> If you want to hear the residual easily (32-bit version inverted, summed 
>>> with 16-bit truncated, the result with +40 dB gain via Trim plug-in):
>>> 
>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav
>>> 
>>> I don’t expect the 16-bit truncated version to bother you, but it does 
>>> bother some audio engineers. Here's 16-bit dithered version, for 
>>> completeness, so that you can decide if the added noise floor bothers you:
>>> 
>>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav
>>> 
>>> 
>>> 
>>>> On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:
>>>> 
>>>> Yes, I disagree with the "always". "Not always needed" means "it's 
>>>> sometimes needed", my point is that it's never needed, until proven 
>>>> otherwise. Your video proves that sometimes it's not needed, but not that 
>>>> sometimes it's needed.
>>>> 
>>>> 
>>>> 
>>>> -Message d'origine- From: Nigel Redmon
>>>> Sent: Wednesday, February 04, 2015 6:51 PM
>>>> To: A discussion list for music-related DSP
>>>> Subject: Re: [music-dsp] Dither video and articles
>>>> 
>>>>> I totally understood the point of your video, that dithering to 16bit 
>>>>> isn't always needed - but that's what I disagree with.
>>>> 
>>>> Sorry, Didier, I’m confused now. I took from your previous message that 
>>>> you feel 16-bit doesn’t need to be dithered ("dithering to 16bit will 
>>>> never make any audible difference”). Here you say that you disagree with 
>>>> "dithering to 16bit isn't always needed”. In fact, you are saying that 
>>>> it’s never needed—you disagree because “isn’t always needed” implies that 
>>>> it is sometimes needed—correct?
>>>> 
>>>> 
>>>>> On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:
>>>>> 
>>>>>>> Then, it’s no-win situation, because I could EASILY manufacture a bit 
>>>>>>> of music that had significant truncation distortion at 16-bit.
>>>>> 
>>>>> Please do, I would really like to hear it.
>>>>> 
>>>>> I have never heard truncation noise at 16bit, other than by playing with 
>>>>> levels in a such a way that the peaking parts of the rest of the sound 
>>>>> would destroy your ears or be very unpleasant at best. (you say 12dB, 
>>>>> it's already a lot)
>>>>> 
>>>>> I totally understood the point of your video, that dithering to 16bit 
>>>>> isn't always needed - but that's what I disagree with.
>>>>> 
>>>>> 
>>>>> 
>>>>> -Message d'origine- From: Nigel Redmon
>>>>> Sent: Wednesday, February 04, 2015 10:59 AM
>>>>> To: A discussion list for music-related DSP
>>>>> Subject: Re: [music-dsp] Dither video and articles
>>>>> 
>>>>> Hi Didier—You seem to find contradictions in my choices because you are 
>>>>> making the wrong assumptions about what I’m showing and saying.
>>>>> 
>>>>> First, I’m not steadfast that 16-bit dither is always needed—and in fact 
>>>>> the point of the video was that I was showing you (the viewers) how you 
>>>>> can judge it objectively for yourself (and decide whether you want to 
>>>>> dither). This is a much better way that the usual that I hear from 
>>>>> people, who often listen to the dithered and non-dithered results, and 
>>>>> talk about the "soundstage collapsing" without dither, “brittle” versus 
>>>>> “transparent" , etc.
>>>>> 
>>>>>

Re: [music-dsp] Dither video and articles

Plenty of people have financial interests in disputing such claims, though. 
While the ones on the other side can't have such interests.

Hey, I've even read marketing poiting out that 64bit summing in sequencers 
was also making an audible difference.

-Message d'origine- 
From: Tom Duffy

Sent: Friday, February 06, 2015 3:50 AM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles

The AES report is highly controversial.

Plenty of sources dispute the findings.

---
Tom

On 2/5/2015 6:39 PM, Ross Bencina wrote:
Hi Ethan,

On 6/02/2015 1:17 PM, Ethan Duni wrote:
 >> There is just no way A/B testing on a sample of listeners,
 >> >at loud, but still realistic listening levels, would show that
 >> >dithering to 16bit makes a difference.
 >
 > Well, can you refer us to an A/B test that confirms your assertions?
 > Personally I take a dim view of people telling me that a test would
surely
 > confirm their assertions, but without actually doing any test.

Here's a double-blind A/B/X test that indicated no one could hear the
difference between 16 and 24 bit. 24-bit is better than 16-bit with
dithering so maybe you can extrapolate.

AES Journal 2007 September, Volume 55 Number 9: "Audibility of a
CD-Standard A/D/A Loop Inserted into High-Resolution Audio Playback"
E. Brad Meyer and David R. Moran

I found this link with google:
http://drewdaniels.com/audible.pdf

"The test results show that the CD-quality A/D/A loop was undetectable
at normal-to-loud listening levels, by any of the subjects, on any of
the playback systems. The noise of the CD-quality loop was audible only
at very elevated levels."

Cheers,

Ross.
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Re: [music-dsp] Dither video and articles


I'm not quite sure I understand what you described here below.
I think the wavs should have contained a normalized part, so that anyone who 
listens to it, will never crank up his volume above the threshold of pain on 
the first, normalized part, and then everyone is more or less listening to 
the quiet part the same way.


Claiming that it's any audible is one thing, but you go as far as saying 
it's clear to hear.. we're probably not testing the same way.
I have normalized (+23dB) the last 9 seconds of the Diva bass 16-bit 
truncated.wav file to hear what I was supposed to hear. I'm just not hearing 
anything close to that, in the normal test.


While I have Sennheiser HD650, I'm listening through bose QC15 because, 
although it's night time, my ambient noise is probably a gazillion times 
above what we're debating here. So I'm in a pretty quiet listening setup 
here (for those who have tried QC15's).




-Message d'origine- 
From: Andrew Simper

Sent: Friday, February 06, 2015 3:31 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

I also tried boosting the float version of the bass tone to -1 dB (so
another 18 dB up from with the same test setup), it was loud, but not
anywhere near the threshold of pain for me. I then boosted it another
12 dB on the headphone control (so 0 dB gain), so now 30 dB gain in
total and my headphones were really shaking, this was a bit silly a
level, but still definitely not painful to listen to. My point being
that this is a very reasonable test signal to listen to, and it is
clear to hear the differences even at low levels of gain.

If I had to choose, between the two 16-bit ones I would prefer the one
with dither but put through a "make mono" plugin, as this sounded the
closest to the float version.

All the best,

Andy

-- cytomic -- sound music software --


On 5 February 2015 at 16:46, Nigel Redmon  wrote:
Hmm, I thought that would let you save the page source (wave file)…Safari 
creates the file of the appropriate name and type, but it stays at 0 
bytes…OK, I put up and index page—do the usual right-click to save the 
field to disk if you need to access the files directly:


http://earlevel.com/temp/music-dsp/



On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:

OK, here’s my new piece, I call it Diva bass—to satisfy your request for 
me to make something with truncation distortion apparent. (If it bother 
you that my piece is one note, imagine that this is just the last note of 
a longer piece.)


I spent maybe 30 seconds getting the sound—opened Diva (default 
 “minimoog” modules), turn the mixer knobs down except for VCO 1, set 
range to 32’, waveform to triangle, max release on the VCA envelope.


In 32-bit float glory:

http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav

Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), 
saved to 16-bit wave file:


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav

You’ll have to turn your sound system up, not insanely loud, but loud. (I 
said that this would be the case before.) I can hear it, and I know 
engineers who monitor much louder, routinely, than I’m monitoring to hear 
this. My Equator Q10s are not terribly high powered, and I’m not adding 
any other gain ahead of them in order to boost the quiet part.


If you want to hear the residual easily (32-bit version inverted, summed 
with 16-bit truncated, the result with +40 dB gain via Trim plug-in):


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav

I don’t expect the 16-bit truncated version to bother you, but it does 
bother some audio engineers. Here's 16-bit dithered version, for 
completeness, so that you can decide if the added noise floor bothers 
you:


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav




On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:

Yes, I disagree with the "always". "Not always needed" means "it's 
sometimes needed", my point is that it's never needed, until proven 
otherwise. Your video proves that sometimes it's not needed, but not 
that sometimes it's needed.




-Message d'origine- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 6:51 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

I totally understood the point of your video, that dithering to 16bit 
isn't always needed - but that's what I disagree with.


Sorry, Didier, I’m confused now. I took from your previous message that 
you feel 16-bit doesn’t need to be dithered ("dithering to 16bit will 
never make any audible difference”). Here you say that you disagree with 
"dithering to 16bit isn't always needed”. In fact, you are saying that 
it’s never needed—you disagree because “isn’t always need

Re: [music-dsp] Dither video and articles

Aren't you an adept of "it's not true until proven otherwise"? Because I'm 
not the one making a claim here. I'm all for a public A/B testing that would 
prove it true. Until then, well it's not true, to me. You can't come up with 
"my audio cables sound better" and say that it's true because the opposite 
hasn't been proven yet.





And again, there are a variety of real-world use cases where the 16 bit
audio from a CD (or whatever) has its dynamic range reduced in the 
playback

chain. Are we supposed to just ignore those use cases?


Wait, are you saying that you would then introduce an even greater dithering 
noise, to mask possible dynamic range reduction in the playback chain? 
Because what has been suggested won't fix that. What would you dither to, 
14bit? That rather goes to the opposite direction of the claim that 
"engineers shouldn't do things according to the lowest common denominator".



A video you should watch as well, btw:
http://xiph.org/video/vid2.shtml




-Message d'origine- 
From: Ethan Duni

Sent: Friday, February 06, 2015 3:17 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles


There is just no way A/B testing on a sample of listeners,
at loud, but still realistic listening levels, would show that
dithering to 16bit makes a difference.


Well, can you refer us to an A/B test that confirms your assertions?
Personally I take a dim view of people telling me that a test would surely
confirm their assertions, but without actually doing any test.

And again, there are a variety of real-world use cases where the 16 bit
audio from a CD (or whatever) has its dynamic range reduced in the playback
chain. Are we supposed to just ignore those use cases?

E
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Re: [music-dsp] Dither video and articles

2015-02-05 Thread Tom Duffy


Easily googled.

Paraphrased from memory:
Insufficient info on equipment used, can't reproduce experiment.
Source probably not greater than 16 bit quality to start with.

---
Tom.

On 2/5/2015 7:01 PM, Ross Bencina wrote:
On 6/02/2015 1:50 PM, Tom Duffy wrote:
The AES report is highly controversial.

Plenty of sources dispute the findings.

Can you name some?

Ross.
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Re: [music-dsp] Dither video and articles

On 6 February 2015 at 09:00, Nigel Redmon  wrote:
>...
> Several people have told me that they can hear it, consistently, on 24-bit 
> truncations. I don’t think so. I read in a forum, where an expert was using 
> some beta software and mentioned the audible difference with engaging 24-bit 
> dither and not via a button on the GUI, and the developer had to tell him 
> that he was mistaken on the function of that button, and that it did not 
> impact audio at all.

I've done tests and 18-bits is pretty much my limit to hear any
differences dither can make, and that is it loud listening levels. At
20-bits I can't tell any difference unless I do something pathological
like only listen to the tail and then boost the crap out of it.

> ...But at 16-bit, it’s just not that hard to hear it—an edge case, for sure, 
> but it’s there, so they will want to act on it, and I don’t think that’s 
> unreasonable.

I agree.

All the best,

Andy
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Re: [music-dsp] Dither video and articles

2015-02-05 Thread Ross Bencina


On 6/02/2015 1:50 PM, Tom Duffy wrote:

The AES report is highly controversial.

Plenty of sources dispute the findings.


Can you name some?

Ross.
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Re: [music-dsp] Dither video and articles

2015-02-05 Thread Tom Duffy

The AES report is highly controversial.

Plenty of sources dispute the findings.

---
Tom

On 2/5/2015 6:39 PM, Ross Bencina wrote:
Hi Ethan,

On 6/02/2015 1:17 PM, Ethan Duni wrote:
 >> There is just no way A/B testing on a sample of listeners,
 >> >at loud, but still realistic listening levels, would show that
 >> >dithering to 16bit makes a difference.
 >
 > Well, can you refer us to an A/B test that confirms your assertions?
 > Personally I take a dim view of people telling me that a test would
surely
 > confirm their assertions, but without actually doing any test.

Here's a double-blind A/B/X test that indicated no one could hear the
difference between 16 and 24 bit. 24-bit is better than 16-bit with
dithering so maybe you can extrapolate.

AES Journal 2007 September, Volume 55 Number 9: "Audibility of a
CD-Standard A/D/A Loop Inserted into High-Resolution Audio Playback"
E. Brad Meyer and David R. Moran

I found this link with google:
http://drewdaniels.com/audible.pdf

"The test results show that the CD-quality A/D/A loop was undetectable
at normal-to-loud listening levels, by any of the subjects, on any of
the playback systems. The noise of the CD-quality loop was audible only
at very elevated levels."

Cheers,

Ross.
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Re: [music-dsp] Dither video and articles

2015-02-05 Thread Ross Bencina

Hi Ethan,

On 6/02/2015 1:17 PM, Ethan Duni wrote:
>> There is just no way A/B testing on a sample of listeners,
>> >at loud, but still realistic listening levels, would show that
>> >dithering to 16bit makes a difference.
>
> Well, can you refer us to an A/B test that confirms your assertions?
> Personally I take a dim view of people telling me that a test would 
surely

> confirm their assertions, but without actually doing any test.

Here's a double-blind A/B/X test that indicated no one could hear the 
difference between 16 and 24 bit. 24-bit is better than 16-bit with 
dithering so maybe you can extrapolate.

AES Journal 2007 September, Volume 55 Number 9: "Audibility of a 
CD-Standard A/D/A Loop Inserted into High-Resolution Audio Playback"

E. Brad Meyer and David R. Moran

I found this link with google:
http://drewdaniels.com/audible.pdf

"The test results show that the CD-quality A/D/A loop was undetectable 
at normal-to-loud listening levels, by any of the subjects, on any of 
the playback systems. The noise of the CD-quality loop was audible only

at very elevated levels."

Cheers,

Ross.
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Re: [music-dsp] Dither video and articles

Hi Nigel,

Can I please ask a favour? Can you please add a "mono noise" button to
your dither plugin? In headphones the sudden onset of stereo hiss of
the dither is pretty obvious and a little distracting in this example.
I had a listen with a "make mono" plugin and the results were much
less obvious between the 16-bit with dither and the float file.  It
would be interesting to hear a stereo source (eg the same Diva sounds
but in unison) put through mono noise dithering.

The differences are pretty clear to me, thanks for posting the files! My setup:

(*) Switching between files randomly the three files randomly playing
them back with unity gain (the float file padded -6 dB to have the
same volume as the others)
(*) FireFace UCX with headphone output set to -12 dB, all other gains at unity
(*) Senheisser Amperior HD25 headphones

My results

(*) the float file is easy to spot, because of the differences when
compared to the other two
(*) the dithered one sounds hissy straight away when I switch to it,
it is obvious that the hiss is stereo, my ears immediately hear that
stereo difference, but otherwise it sounds like the original float
file
(*) the undithered one, right from the start, sounds like a harsher
version of the float one with just a hint of noise as well, an
aggressive subtle edge to the tone which just isn't in the original.
When the fadeout comes then it becomes more obvious aliasing
distortion that everyone is used to hearing.

I also tried boosting the float version of the bass tone to -1 dB (so
another 18 dB up from with the same test setup), it was loud, but not
anywhere near the threshold of pain for me. I then boosted it another
12 dB on the headphone control (so 0 dB gain), so now 30 dB gain in
total and my headphones were really shaking, this was a bit silly a
level, but still definitely not painful to listen to. My point being
that this is a very reasonable test signal to listen to, and it is
clear to hear the differences even at low levels of gain.

If I had to choose, between the two 16-bit ones I would prefer the one
with dither but put through a "make mono" plugin, as this sounded the
closest to the float version.

All the best,

Andy

-- cytomic -- sound music software --

On 5 February 2015 at 16:46, Nigel Redmon  wrote:
> Hmm, I thought that would let you save the page source (wave file)…Safari 
> creates the file of the appropriate name and type, but it stays at 0 
> bytes…OK, I put up and index page—do the usual right-click to save the field 
> to disk if you need to access the files directly:
>
> http://earlevel.com/temp/music-dsp/
>
>
>> On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:
>>
>> OK, here’s my new piece, I call it Diva bass—to satisfy your request for me 
>> to make something with truncation distortion apparent. (If it bother you 
>> that my piece is one note, imagine that this is just the last note of a 
>> longer piece.)
>>
>> I spent maybe 30 seconds getting the sound—opened Diva (default “minimoog” 
>> modules), turn the mixer knobs down except for VCO 1, set range to 32’, 
>> waveform to triangle, max release on the VCA envelope.
>>
>> In 32-bit float glory:
>>
>> http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav
>>
>> Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), saved 
>> to 16-bit wave file:
>>
>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
>>
>> You’ll have to turn your sound system up, not insanely loud, but loud. (I 
>> said that this would be the case before.) I can hear it, and I know 
>> engineers who monitor much louder, routinely, than I’m monitoring to hear 
>> this. My Equator Q10s are not terribly high powered, and I’m not adding any 
>> other gain ahead of them in order to boost the quiet part.
>>
>> If you want to hear the residual easily (32-bit version inverted, summed 
>> with 16-bit truncated, the result with +40 dB gain via Trim plug-in):
>>
>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav
>>
>> I don’t expect the 16-bit truncated version to bother you, but it does 
>> bother some audio engineers. Here's 16-bit dithered version, for 
>> completeness, so that you can decide if the added noise floor bothers you:
>>
>> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav
>>
>>
>>
>>> On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:
>>>
>>> Yes, I disagree with the "always". "Not always needed" means "it's 
>>> sometimes needed", my point is that it's never needed, until proven 
>>> otherwise. Your video proves that sometimes it&#x

Re: [music-dsp] Dither video and articles

2015-02-05 Thread Ethan Duni

>There is just no way A/B testing on a sample of listeners,
>at loud, but still realistic listening levels, would show that
>dithering to 16bit makes a difference.

Well, can you refer us to an A/B test that confirms your assertions?
Personally I take a dim view of people telling me that a test would surely
confirm their assertions, but without actually doing any test.

And again, there are a variety of real-world use cases where the 16 bit
audio from a CD (or whatever) has its dynamic range reduced in the playback
chain. Are we supposed to just ignore those use cases?

E
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Re: [music-dsp] Dither video and articles

What I wrote is that 16bit audio only applies to the end listener, that is, 
it's aimed at the end listener, not the professional who will reuse the bit 
of audio. There is just no way A/B testing on a sample of listeners, at 
loud, but still realistic listening levels, would show that dithering to 
16bit makes a difference.



Sure, or FM radio in a car on a cheap system. But a mastering engineer 
isn’t going to factor in the lowest common denominator, any more than a 
photographer is going to assume that his photo will end up in black and 
white newsprint


An engineer has very important work to do on mastering (I would say in 
rather destructive ways, *because* our perception is rather forgiving), but 
that doesn't make dithering to 16bit less snake oil.



Several people have told me that they can hear it, consistently, on 
24-bit truncations.


yeah I hear things like that (or worse) all day long. But to be honnest, 
even I have ended up tweaking parameters of a switched off effect, until I 
was happy with the result.





-Message d'origine- 
From: Nigel Redmon

Sent: Friday, February 06, 2015 2:00 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Yes, because that's the only thing 16bit audio applies to, the end 
listener.


??? They have absolutely no control over it. The decision to dither or not 
was made before they hear it. My advice is not to them. I get asked 
questions about dither from the people who do the reduction to 16-bit, not 
your average music listener. I have another video that explains what dither 
is and how it works, for the curious, but I get asked for my opinion, so I 
made this video. (Often, the people who ask already have their own opinion, 
and want to see if I’m on their side. And often, what follows is a spirited 
debate about 24-bit dither, not 16-bit.)


Talking about this, in a world where the end listener almost always listens 
in lossy encoded formats, the 16bit quantization problem isn't even a 
shrimp in the whole universe.


Sure, or FM radio in a car on a cheap system. But a mastering engineer isn’t 
going to factor in the lowest common denominator, any more than a 
photographer is going to assume that his photo will end up in black and 
white newsprint, or a movie director will assume that his work is going to 
be cropped to fit an old tube set and broadcast for pickup on rabbit ears. 
:-) If you tell a recording or mastering engineer that nobody can hear this 
stuff, they’ll crank the monitors and say, “you can’t hear THAT crap?” End 
of story.


Of course, they’ll often “hear” it when it isn’t really there too, which is 
why I showed a more objective way of listening for it. Several people have 
told me that they can hear it, consistently, on 24-bit truncations. I don’t 
think so. I read in a forum, where an expert was using some beta software 
and mentioned the audible difference with engaging 24-bit dither and not via 
a button on the GUI, and the developer had to tell him that he was mistaken 
on the function of that button, and that it did not impact audio at all. (I’m 
not making fun of the guy, and I admire his work, it’s just that anyone who 
does serious audio work fools themselves into thinking they hear something 
that is not, occasionally—fact of life.) But at 16-bit, it’s just not that 
hard to hear it—an edge case, for sure, but it’s there, so they will want to 
act on it, and I don’t think that’s unreasonable.




On Feb 5, 2015, at 3:15 PM, Didier Dambrin  wrote:

But the key here is *bits*. If you're listening at normal levels, those 
parts in music that "don't use all 16bits" (which is obvious, you can find 
parts of all levels in a song) will be quieter, & thus the noise will be 
less audible.


Put a sine wave in the lowest 1 or 2 bits of a 16bit piece of audio, it 
should be horrible noise, right? If you crank up your volume until you 
hear that sinewave, obviously it will. But at normal listening level, are 
you really gonna hear that sinewave or worse, its horrible noise? My bet 
would be *maybe*, in an anechoic room, after a couple of hours of getting 
used to silence.




he cost is virtual nothing


I will certainly not disagree with that, it doesn't hurt & costs (almost) 
nothing. But it's still snake oil.




Our biggest difference is that you are looking at this from the 
end-listener point of view.


Yes, because that's the only thing 16bit audio applies to, the end 
listener. Ok, apparently some still need to publish 16bit audio files for 
pro's because not every tool out there (I guess) supports 24 (& I would 
still advise against storing in integer format at all) or 32bit formats - 
this is most likely not gonna last very long.
Talking about this, in a world where the end listener almost always 
listens in lossy encoded formats, the 16bit quantization problem isn't 
even a shrimp in the who

Re: [music-dsp] Dither video and articles

>Yes, because that's the only thing 16bit audio applies to, the end listener.

??? They have absolutely no control over it. The decision to dither or not was 
made before they hear it. My advice is not to them. I get asked questions about 
dither from the people who do the reduction to 16-bit, not your average music 
listener. I have another video that explains what dither is and how it works, 
for the curious, but I get asked for my opinion, so I made this video. (Often, 
the people who ask already have their own opinion, and want to see if I’m on 
their side. And often, what follows is a spirited debate about 24-bit dither, 
not 16-bit.)

>Talking about this, in a world where the end listener almost always listens in 
>lossy encoded formats, the 16bit quantization problem isn't even a shrimp in 
>the whole universe.

Sure, or FM radio in a car on a cheap system. But a mastering engineer isn’t 
going to factor in the lowest common denominator, any more than a photographer 
is going to assume that his photo will end up in black and white newsprint, or 
a movie director will assume that his work is going to be cropped to fit an old 
tube set and broadcast for pickup on rabbit ears. :-) If you tell a recording 
or mastering engineer that nobody can hear this stuff, they’ll crank the 
monitors and say, “you can’t hear THAT crap?” End of story.

Of course, they’ll often “hear” it when it isn’t really there too, which is why 
I showed a more objective way of listening for it. Several people have told me 
that they can hear it, consistently, on 24-bit truncations. I don’t think so. I 
read in a forum, where an expert was using some beta software and mentioned the 
audible difference with engaging 24-bit dither and not via a button on the GUI, 
and the developer had to tell him that he was mistaken on the function of that 
button, and that it did not impact audio at all. (I’m not making fun of the 
guy, and I admire his work, it’s just that anyone who does serious audio work 
fools themselves into thinking they hear something that is not, 
occasionally—fact of life.) But at 16-bit, it’s just not that hard to hear 
it—an edge case, for sure, but it’s there, so they will want to act on it, and 
I don’t think that’s unreasonable.

> On Feb 5, 2015, at 3:15 PM, Didier Dambrin  wrote:
> 
> But the key here is *bits*. If you're listening at normal levels, those parts 
> in music that "don't use all 16bits" (which is obvious, you can find parts of 
> all levels in a song) will be quieter, & thus the noise will be less audible.
> 
> Put a sine wave in the lowest 1 or 2 bits of a 16bit piece of audio, it 
> should be horrible noise, right? If you crank up your volume until you hear 
> that sinewave, obviously it will. But at normal listening level, are you 
> really gonna hear that sinewave or worse, its horrible noise? My bet would be 
> *maybe*, in an anechoic room, after a couple of hours of getting used to 
> silence.
> 
> 
>>> he cost is virtual nothing
> 
> I will certainly not disagree with that, it doesn't hurt & costs (almost) 
> nothing. But it's still snake oil.
> 
> 
> 
>>> Our biggest difference is that you are looking at this from the 
>>> end-listener point of view.
> 
> Yes, because that's the only thing 16bit audio applies to, the end listener. 
> Ok, apparently some still need to publish 16bit audio files for pro's because 
> not every tool out there (I guess) supports 24 (& I would still advise 
> against storing in integer format at all) or 32bit formats - this is most 
> likely not gonna last very long.
> Talking about this, in a world where the end listener almost always listens 
> in lossy encoded formats, the 16bit quantization problem isn't even a shrimp 
> in the whole universe.
> 
> 
> 
> 
> 
> 
> 
> -Message d'origine- From: Nigel Redmon
> Sent: Thursday, February 05, 2015 7:13 PM
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
> 
> Music is not typically full scale. My level was arbitrary—where the mixer 
> knob happened to be sitting—but the note is relatively loud in a musical 
> setting.
> 
> You don’t get to use all 16 bits, all the time in music. So, to complain that 
> it might as well be 13-bit…well, if we had 13-bit converters and sample size, 
> we’d be having this discussion about 10-bit. The bass note is LOUD, compared 
> to similar bits in actual music, as I’m playing from iTunes right now.
> 
> OK, I’m not trying to convince you—it was obvious that we’d have to agree to 
> disagree on this. And, as you know, I’m not overstating the importance of 
> dithering 16-bit audio, as many others do. I’m simply saying that it’s worth 
> it—the cost is virtual not

Re: [music-dsp] Dither video and articles

But the key here is *bits*. If you're listening at normal levels, those 
parts in music that "don't use all 16bits" (which is obvious, you can find 
parts of all levels in a song) will be quieter, & thus the noise will be 
less audible.


Put a sine wave in the lowest 1 or 2 bits of a 16bit piece of audio, it 
should be horrible noise, right? If you crank up your volume until you hear 
that sinewave, obviously it will. But at normal listening level, are you 
really gonna hear that sinewave or worse, its horrible noise? My bet would 
be *maybe*, in an anechoic room, after a couple of hours of getting used to 
silence.




he cost is virtual nothing


I will certainly not disagree with that, it doesn't hurt & costs (almost) 
nothing. But it's still snake oil.




Our biggest difference is that you are looking at this from the 
end-listener point of view.


Yes, because that's the only thing 16bit audio applies to, the end listener. 
Ok, apparently some still need to publish 16bit audio files for pro's 
because not every tool out there (I guess) supports 24 (& I would still 
advise against storing in integer format at all) or 32bit formats - this is 
most likely not gonna last very long.
Talking about this, in a world where the end listener almost always listens 
in lossy encoded formats, the 16bit quantization problem isn't even a shrimp 
in the whole universe.








-Message d'origine- 
From: Nigel Redmon

Sent: Thursday, February 05, 2015 7:13 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Music is not typically full scale. My level was arbitrary—where the mixer 
knob happened to be sitting—but the note is relatively loud in a musical 
setting.


You don’t get to use all 16 bits, all the time in music. So, to complain 
that it might as well be 13-bit…well, if we had 13-bit converters and sample 
size, we’d be having this discussion about 10-bit. The bass note is LOUD, 
compared to similar bits in actual music, as I’m playing from iTunes right 
now.


OK, I’m not trying to convince you—it was obvious that we’d have to agree to 
disagree on this. And, as you know, I’m not overstating the importance of 
dithering 16-bit audio, as many others do. I’m simply saying that it’s worth 
it—the cost is virtual nothing (it’s not even don’t in real time, but just 
for the final bounce to disk), doing it doesn’t harm the music in any way 
(if you can hear the distortion, I don’t think you’ll hear 16-bit flat 
dither).


Our biggest difference is that you are looking at this from the end-listener 
point of view. But why would I be giving advice to the listener? They aren’t 
the ones making the choice to dither or not. The advice is for people in the 
position of dithering. And these people do hear it. If my advice were “Don’t 
bother—you can’t hear it anyway”, these people would think I’m an idiot—of 
course they can hear it. Their business is to look for junk and grunge and 
get rid of it. I can envision Bob Katz, Bob Olson, and Bruce Swedien 
knocking at my door, wanting to beat me with a microphone stand and pop 
screens for telling them that they can’t hear this stuff. (Just kidding, 
they seem like really nice guys.)


The funny thing is that I’m arguing in favor of 16-bit dither with you, and 
having a similar exchange with a mastering engineer, who is sending me 
examples of why we really must dither at 24-bit ...




On Feb 5, 2015, at 9:49 AM, Didier Dambrin  wrote:


If you mean that the peak loudness of the synth isn’t hitting full scale


Yeah I mean that, since, to compensate, you crank your volume up, making 
it 13bit worth (from 14bit, after your extra -6dB gain)


I mean it's always the same debate with dithering, one could demonstrate 
exactly the same with 8bit worth of audio in a 16bit file. To me a 16bit 
file is 16bit worth of audio, for the whole project, thus with the loudest 
parts of the project designed to be listened to. If the entire project 
peaks at -18dB, then it's not designed to be listened to at the same level 
as other 16bit files, and thus it's not 16bit worth of audio. One could go 
further & store 1 bit worth of audio in a 16bit file and point out how 
degraded it is.
Quantization & loss is everywhere in a computer (obviously) and magnifying 
it doesn't make a point, because you always can bring the imperceptible 
back to perception. To me it's all about what's perceptible when the 
project is used as intended, otherwise, even 64bit float audio should be 
marked as "lossy".



I could have had a louder sound with a similar tail that would have 
produced the same distortion.


yeah, except that louder sound would have killed your ears, so you would 
have cranked your listening level down, and not heard the noise anymore






-Message d'origine- From: Nigel Redmon
Sent: Thursday, February 05, 2015 6:22

Re: [music-dsp] Dither video and articles

"Bob Ohlsson"—not sure if I really typed it that way or if it got 
autocorrected...

> On Feb 5, 2015, at 10:13 AM, Nigel Redmon  wrote:
> 
> Music is not typically full scale. My level was arbitrary—where the mixer 
> knob happened to be sitting—but the note is relatively loud in a musical 
> setting.
> 
> You don’t get to use all 16 bits, all the time in music. So, to complain that 
> it might as well be 13-bit…well, if we had 13-bit converters and sample size, 
> we’d be having this discussion about 10-bit. The bass note is LOUD, compared 
> to similar bits in actual music, as I’m playing from iTunes right now.
> 
> OK, I’m not trying to convince you—it was obvious that we’d have to agree to 
> disagree on this. And, as you know, I’m not overstating the importance of 
> dithering 16-bit audio, as many others do. I’m simply saying that it’s worth 
> it—the cost is virtual nothing (it’s not even don’t in real time, but just 
> for the final bounce to disk), doing it doesn’t harm the music in any way (if 
> you can hear the distortion, I don’t think you’ll hear 16-bit flat dither).
> 
> Our biggest difference is that you are looking at this from the end-listener 
> point of view. But why would I be giving advice to the listener? They aren’t 
> the ones making the choice to dither or not. The advice is for people in the 
> position of dithering. And these people do hear it. If my advice were “Don’t 
> bother—you can’t hear it anyway”, these people would think I’m an idiot—of 
> course they can hear it. Their business is to look for junk and grunge and 
> get rid of it. I can envision Bob Katz, Bob Olson, and Bruce Swedien knocking 
> at my door, wanting to beat me with a microphone stand and pop screens for 
> telling them that they can’t hear this stuff. (Just kidding, they seem like 
> really nice guys.)
> 
> The funny thing is that I’m arguing in favor of 16-bit dither with you, and 
> having a similar exchange with a mastering engineer, who is sending me 
> examples of why we really must dither at 24-bit ...
> 
> 
>> On Feb 5, 2015, at 9:49 AM, Didier Dambrin  wrote:
>> 
>>>> If you mean that the peak loudness of the synth isn’t hitting full scale
>> 
>> Yeah I mean that, since, to compensate, you crank your volume up, making it 
>> 13bit worth (from 14bit, after your extra -6dB gain)
>> 
>> I mean it's always the same debate with dithering, one could demonstrate 
>> exactly the same with 8bit worth of audio in a 16bit file. To me a 16bit 
>> file is 16bit worth of audio, for the whole project, thus with the loudest 
>> parts of the project designed to be listened to. If the entire project peaks 
>> at -18dB, then it's not designed to be listened to at the same level as 
>> other 16bit files, and thus it's not 16bit worth of audio. One could go 
>> further & store 1 bit worth of audio in a 16bit file and point out how 
>> degraded it is.
>> Quantization & loss is everywhere in a computer (obviously) and magnifying 
>> it doesn't make a point, because you always can bring the imperceptible back 
>> to perception. To me it's all about what's perceptible when the project is 
>> used as intended, otherwise, even 64bit float audio should be marked as 
>> "lossy".
>> 
>> 
>>>> I could have had a louder sound with a similar tail that would have 
>>>> produced the same distortion.
>> 
>> yeah, except that louder sound would have killed your ears, so you would 
>> have cranked your listening level down, and not heard the noise anymore
>> 
>> 
>> 
>> 
>> 
>> -Message d'origine- From: Nigel Redmon
>> Sent: Thursday, February 05, 2015 6:22 PM
>> To: A discussion list for music-related DSP
>> Subject: Re: [music-dsp] Dither video and articles
>> 
>> Oh, sorry about the 6 dB. I made the 16- and 32-bit versions, then noticed I 
>> had the gain slider on the DP mixer pushed up. I pulled it back to 0 dB and 
>> made new bounces, plus the residual and dithered version subsequently, but 
>> must have grabbed the wrong 32-bit version for upload.
>> 
>> I have no idea what you’re implying about "IMHO this is 13bit worth of audio 
>> inside a 16bit file”. I took care to have no gain after the truncation 
>> (except the accidental 6 dB on the 32-bit file). If you mean that the peak 
>> loudness of the synth isn’t hitting full scale, then, A) welcome to music, 
>> and B) it’s immaterial—I could have had a louder sound with a similar tail 
>> that would have produced the same distortion.
>> 
>> I’m not surprised you couldn’t hear it, as I s

Re: [music-dsp] Dither video and articles

Music is not typically full scale. My level was arbitrary—where the mixer knob 
happened to be sitting—but the note is relatively loud in a musical setting.

You don’t get to use all 16 bits, all the time in music. So, to complain that 
it might as well be 13-bit…well, if we had 13-bit converters and sample size, 
we’d be having this discussion about 10-bit. The bass note is LOUD, compared to 
similar bits in actual music, as I’m playing from iTunes right now.

OK, I’m not trying to convince you—it was obvious that we’d have to agree to 
disagree on this. And, as you know, I’m not overstating the importance of 
dithering 16-bit audio, as many others do. I’m simply saying that it’s worth 
it—the cost is virtual nothing (it’s not even don’t in real time, but just for 
the final bounce to disk), doing it doesn’t harm the music in any way (if you 
can hear the distortion, I don’t think you’ll hear 16-bit flat dither).

Our biggest difference is that you are looking at this from the end-listener 
point of view. But why would I be giving advice to the listener? They aren’t 
the ones making the choice to dither or not. The advice is for people in the 
position of dithering. And these people do hear it. If my advice were “Don’t 
bother—you can’t hear it anyway”, these people would think I’m an idiot—of 
course they can hear it. Their business is to look for junk and grunge and get 
rid of it. I can envision Bob Katz, Bob Olson, and Bruce Swedien knocking at my 
door, wanting to beat me with a microphone stand and pop screens for telling 
them that they can’t hear this stuff. (Just kidding, they seem like really nice 
guys.)

The funny thing is that I’m arguing in favor of 16-bit dither with you, and 
having a similar exchange with a mastering engineer, who is sending me examples 
of why we really must dither at 24-bit ...

> On Feb 5, 2015, at 9:49 AM, Didier Dambrin  wrote:
> 
>>> If you mean that the peak loudness of the synth isn’t hitting full scale
> 
> Yeah I mean that, since, to compensate, you crank your volume up, making it 
> 13bit worth (from 14bit, after your extra -6dB gain)
> 
> I mean it's always the same debate with dithering, one could demonstrate 
> exactly the same with 8bit worth of audio in a 16bit file. To me a 16bit file 
> is 16bit worth of audio, for the whole project, thus with the loudest parts 
> of the project designed to be listened to. If the entire project peaks at 
> -18dB, then it's not designed to be listened to at the same level as other 
> 16bit files, and thus it's not 16bit worth of audio. One could go further & 
> store 1 bit worth of audio in a 16bit file and point out how degraded it is.
> Quantization & loss is everywhere in a computer (obviously) and magnifying it 
> doesn't make a point, because you always can bring the imperceptible back to 
> perception. To me it's all about what's perceptible when the project is used 
> as intended, otherwise, even 64bit float audio should be marked as "lossy".
> 
> 
>>> I could have had a louder sound with a similar tail that would have 
>>> produced the same distortion.
> 
> yeah, except that louder sound would have killed your ears, so you would have 
> cranked your listening level down, and not heard the noise anymore
> 
> 
> 
> 
> 
> -----Message d'origine----- From: Nigel Redmon
> Sent: Thursday, February 05, 2015 6:22 PM
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
> 
> Oh, sorry about the 6 dB. I made the 16- and 32-bit versions, then noticed I 
> had the gain slider on the DP mixer pushed up. I pulled it back to 0 dB and 
> made new bounces, plus the residual and dithered version subsequently, but 
> must have grabbed the wrong 32-bit version for upload.
> 
> I have no idea what you’re implying about "IMHO this is 13bit worth of audio 
> inside a 16bit file”. I took care to have no gain after the truncation 
> (except the accidental 6 dB on the 32-bit file). If you mean that the peak 
> loudness of the synth isn’t hitting full scale, then, A) welcome to music, 
> and B) it’s immaterial—I could have had a louder sound with a similar tail 
> that would have produced the same distortion.
> 
> I’m not surprised you couldn’t hear it, as I said it required fairly high 
> listening levels and I don’t know what your equipment is. It can be heard on 
> a professional monitoring system. I’m monitoring off my TASCAM DM-3200, and 
> it does not have a loud headphone amp—I can’t hear it there. But it’s right 
> on the edge—if I boost it +6 dB I have no problem hearing it. But my 
> monitoring speakers get louder than the headphones, so I can hear it there. 
> And I know engineers who routinely monitor much louder than my gear can get.
> 
> 
&

Re: [music-dsp] Dither video and articles


If you mean that the peak loudness of the synth isn’t hitting full scale


Yeah I mean that, since, to compensate, you crank your volume up, making it 
13bit worth (from 14bit, after your extra -6dB gain)


I mean it's always the same debate with dithering, one could demonstrate 
exactly the same with 8bit worth of audio in a 16bit file. To me a 16bit 
file is 16bit worth of audio, for the whole project, thus with the loudest 
parts of the project designed to be listened to. If the entire project peaks 
at -18dB, then it's not designed to be listened to at the same level as 
other 16bit files, and thus it's not 16bit worth of audio. One could go 
further & store 1 bit worth of audio in a 16bit file and point out how 
degraded it is.
Quantization & loss is everywhere in a computer (obviously) and magnifying 
it doesn't make a point, because you always can bring the imperceptible back 
to perception. To me it's all about what's perceptible when the project is 
used as intended, otherwise, even 64bit float audio should be marked as 
"lossy".



I could have had a louder sound with a similar tail that would have 
produced the same distortion.


yeah, except that louder sound would have killed your ears, so you would 
have cranked your listening level down, and not heard the noise anymore






-Message d'origine- 
From: Nigel Redmon

Sent: Thursday, February 05, 2015 6:22 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Oh, sorry about the 6 dB. I made the 16- and 32-bit versions, then noticed I 
had the gain slider on the DP mixer pushed up. I pulled it back to 0 dB and 
made new bounces, plus the residual and dithered version subsequently, but 
must have grabbed the wrong 32-bit version for upload.


I have no idea what you’re implying about "IMHO this is 13bit worth of audio 
inside a 16bit file”. I took care to have no gain after the truncation 
(except the accidental 6 dB on the 32-bit file). If you mean that the peak 
loudness of the synth isn’t hitting full scale, then, A) welcome to music, 
and B) it’s immaterial—I could have had a louder sound with a similar tail 
that would have produced the same distortion.


I’m not surprised you couldn’t hear it, as I said it required fairly high 
listening levels and I don’t know what your equipment is. It can be heard on 
a professional monitoring system. I’m monitoring off my TASCAM DM-3200, and 
it does not have a loud headphone amp—I can’t hear it there. But it’s right 
on the edge—if I boost it +6 dB I have no problem hearing it. But my 
monitoring speakers get louder than the headphones, so I can hear it there. 
And I know engineers who routinely monitor much louder than my gear can get.




On Feb 5, 2015, at 4:55 AM, Didier Dambrin  wrote:

I couldn't hear any difference (through headphones), even after an insane 
boost, and even though your 16bit truncated wav was 6dB(?) lower than the 
32bit wav


But even if I could hear it, IMHO this is 13bit worth of audio inside a 
16bit file.





-Message d'origine- From: Nigel Redmon
Sent: Thursday, February 05, 2015 9:13 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

OK, here’s my new piece, I call it Diva bass—to satisfy your request for 
me to make something with truncation distortion apparent. (If it bother 
you that my piece is one note, imagine that this is just the last note of 
a longer piece.)


I spent maybe 30 seconds getting the sound—opened Diva (default “minimoog” 
modules), turn the mixer knobs down except for VCO 1, set range to 32’, 
waveform to triangle, max release on the VCA envelope.


In 32-bit float glory:

http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav

Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), saved 
to 16-bit wave file:


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav

You’ll have to turn your sound system up, not insanely loud, but loud. (I 
said that this would be the case before.) I can hear it, and I know 
engineers who monitor much louder, routinely, than I’m monitoring to hear 
this. My Equator Q10s are not terribly high powered, and I’m not adding 
any other gain ahead of them in order to boost the quiet part.


If you want to hear the residual easily (32-bit version inverted, summed 
with 16-bit truncated, the result with +40 dB gain via Trim plug-in):


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav

I don’t expect the 16-bit truncated version to bother you, but it does 
bother some audio engineers. Here's 16-bit dithered version, for 
completeness, so that you can decide if the added noise floor bothers you:


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav




On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:

Yes, I disagree with the "alwa

Re: [music-dsp] Dither video and articles

Oh, sorry about the 6 dB. I made the 16- and 32-bit versions, then noticed I 
had the gain slider on the DP mixer pushed up. I pulled it back to 0 dB and 
made new bounces, plus the residual and dithered version subsequently, but must 
have grabbed the wrong 32-bit version for upload.

I have no idea what you’re implying about "IMHO this is 13bit worth of audio 
inside a 16bit file”. I took care to have no gain after the truncation (except 
the accidental 6 dB on the 32-bit file). If you mean that the peak loudness of 
the synth isn’t hitting full scale, then, A) welcome to music, and B) it’s 
immaterial—I could have had a louder sound with a similar tail that would have 
produced the same distortion.

I’m not surprised you couldn’t hear it, as I said it required fairly high 
listening levels and I don’t know what your equipment is. It can be heard on a 
professional monitoring system. I’m monitoring off my TASCAM DM-3200, and it 
does not have a loud headphone amp—I can’t hear it there. But it’s right on the 
edge—if I boost it +6 dB I have no problem hearing it. But my monitoring 
speakers get louder than the headphones, so I can hear it there. And I know 
engineers who routinely monitor much louder than my gear can get.


> On Feb 5, 2015, at 4:55 AM, Didier Dambrin  wrote:
> 
> I couldn't hear any difference (through headphones), even after an insane 
> boost, and even though your 16bit truncated wav was 6dB(?) lower than the 
> 32bit wav
> 
> But even if I could hear it, IMHO this is 13bit worth of audio inside a 16bit 
> file.
> 
> 
> 
> 
> -Message d'origine- From: Nigel Redmon
> Sent: Thursday, February 05, 2015 9:13 AM
> To: A discussion list for music-related DSP
> Subject: Re: [music-dsp] Dither video and articles
> 
> OK, here’s my new piece, I call it Diva bass—to satisfy your request for me 
> to make something with truncation distortion apparent. (If it bother you that 
> my piece is one note, imagine that this is just the last note of a longer 
> piece.)
> 
> I spent maybe 30 seconds getting the sound—opened Diva (default “minimoog” 
> modules), turn the mixer knobs down except for VCO 1, set range to 32’, 
> waveform to triangle, max release on the VCA envelope.
> 
> In 32-bit float glory:
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav
> 
> Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), saved to 
> 16-bit wave file:
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
> 
> You’ll have to turn your sound system up, not insanely loud, but loud. (I 
> said that this would be the case before.) I can hear it, and I know engineers 
> who monitor much louder, routinely, than I’m monitoring to hear this. My 
> Equator Q10s are not terribly high powered, and I’m not adding any other gain 
> ahead of them in order to boost the quiet part.
> 
> If you want to hear the residual easily (32-bit version inverted, summed with 
> 16-bit truncated, the result with +40 dB gain via Trim plug-in):
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav
> 
> I don’t expect the 16-bit truncated version to bother you, but it does bother 
> some audio engineers. Here's 16-bit dithered version, for completeness, so 
> that you can decide if the added noise floor bothers you:
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav
> 
> 
> 
>> On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:
>> 
>> Yes, I disagree with the "always". "Not always needed" means "it's sometimes 
>> needed", my point is that it's never needed, until proven otherwise. Your 
>> video proves that sometimes it's not needed, but not that sometimes it's 
>> needed.
>> 
>> 
>> 
>> -Message d'origine- From: Nigel Redmon
>> Sent: Wednesday, February 04, 2015 6:51 PM
>> To: A discussion list for music-related DSP
>> Subject: Re: [music-dsp] Dither video and articles
>> 
>>> I totally understood the point of your video, that dithering to 16bit isn't 
>>> always needed - but that's what I disagree with.
>> 
>> Sorry, Didier, I’m confused now. I took from your previous message that you 
>> feel 16-bit doesn’t need to be dithered ("dithering to 16bit will never make 
>> any audible difference”). Here you say that you disagree with "dithering to 
>> 16bit isn't always needed”. In fact, you are saying that it’s never 
>> needed—you disagree because “isn’t always needed” implies that it is 
>> sometimes needed—correct?
>> 
>> 
>>> On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:
>>

Re: [music-dsp] Dither video and articles

2015-02-05 Thread Andreas Beisler

Yes, definitely. Sure, it's a louder level that I would use in casual 
music listening. But it's far from the pain threshold.


Andreas



On 2/5/2015 4:47 PM, Didier Dambrin wrote:

But then I would hear that covering noise..

At the level you listened to, can you listen to a normalized song and
bear it?



-Message d'origine- From: Andreas Beisler
Sent: Thursday, February 05, 2015 4:22 PM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles

The artifacts are very prominent in the tail end of the truncated file.
I don't understand how you cannot hear it. Must be covered by the noise
floor of your sound card's converters.

Andreas



On 2/5/2015 1:55 PM, Didier Dambrin wrote:

I couldn't hear any difference (through headphones), even after an
insane boost, and even though your 16bit truncated wav was 6dB(?) lower
than the 32bit wav

But even if I could hear it, IMHO this is 13bit worth of audio inside a
16bit file.




-Message d'origine- From: Nigel Redmon
Sent: Thursday, February 05, 2015 9:13 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

OK, here’s my new piece, I call it Diva bass—to satisfy your request for
me to make something with truncation distortion apparent. (If it bother
you that my piece is one note, imagine that this is just the last note
of a longer piece.)

I spent maybe 30 seconds getting the sound—opened Diva (default
“minimoog” modules), turn the mixer knobs down except for VCO 1, set
range to 32’, waveform to triangle, max release on the VCA envelope.

In 32-bit float glory:

http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav

Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer),
saved to 16-bit wave file:

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav

You’ll have to turn your sound system up, not insanely loud, but loud.
(I said that this would be the case before.) I can hear it, and I know
engineers who monitor much louder, routinely, than I’m monitoring to
hear this. My Equator Q10s are not terribly high powered, and I’m not
adding any other gain ahead of them in order to boost the quiet part.

If you want to hear the residual easily (32-bit version inverted, summed
with 16-bit truncated, the result with +40 dB gain via Trim plug-in):

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav



I don’t expect the 16-bit truncated version to bother you, but it does
bother some audio engineers. Here's 16-bit dithered version, for
completeness, so that you can decide if the added noise floor bothers
you:

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav




On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:

Yes, I disagree with the "always". "Not always needed" means "it's
sometimes needed", my point is that it's never needed, until proven
otherwise. Your video proves that sometimes it's not needed, but not
that sometimes it's needed.



-Message d'origine- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 6:51 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles


I totally understood the point of your video, that dithering to 16bit
isn't always needed - but that's what I disagree with.


Sorry, Didier, I’m confused now. I took from your previous message
that you feel 16-bit doesn’t need to be dithered ("dithering to 16bit
will never make any audible difference”). Here you say that you
disagree with "dithering to 16bit isn't always needed”. In fact, you
are saying that it’s never needed—you disagree because “isn’t always
needed” implies that it is sometimes needed—correct?



On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:


Then, it’s no-win situation, because I could EASILY manufacture a
bit of music that had significant truncation distortion at 16-bit.


Please do, I would really like to hear it.

I have never heard truncation noise at 16bit, other than by playing
with levels in a such a way that the peaking parts of the rest of the
sound would destroy your ears or be very unpleasant at best. (you say
12dB, it's already a lot)

I totally understood the point of your video, that dithering to 16bit
isn't always needed - but that's what I disagree with.



-Message d'origine- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 10:59 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Hi Didier—You seem to find contradictions in my choices because you
are making the wrong assumptions about what I’m showing and saying.

First, I’m not steadfast that 16-bit dither is always needed—and in
fact the point of the video was that I was showing you (the viewers)
how you can judge it objectively for yourself (and decide whet

Re: [music-dsp] Dither video and articles


But then I would hear that covering noise..

At the level you listened to, can you listen to a normalized song and bear 
it?




-Message d'origine- 
From: Andreas Beisler

Sent: Thursday, February 05, 2015 4:22 PM
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Dither video and articles

The artifacts are very prominent in the tail end of the truncated file.
I don't understand how you cannot hear it. Must be covered by the noise
floor of your sound card's converters.

Andreas



On 2/5/2015 1:55 PM, Didier Dambrin wrote:

I couldn't hear any difference (through headphones), even after an
insane boost, and even though your 16bit truncated wav was 6dB(?) lower
than the 32bit wav

But even if I could hear it, IMHO this is 13bit worth of audio inside a
16bit file.




-Message d'origine- From: Nigel Redmon
Sent: Thursday, February 05, 2015 9:13 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

OK, here’s my new piece, I call it Diva bass—to satisfy your request for
me to make something with truncation distortion apparent. (If it bother
you that my piece is one note, imagine that this is just the last note
of a longer piece.)

I spent maybe 30 seconds getting the sound—opened Diva (default
“minimoog” modules), turn the mixer knobs down except for VCO 1, set
range to 32’, waveform to triangle, max release on the VCA envelope.

In 32-bit float glory:

http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav

Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer),
saved to 16-bit wave file:

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav

You’ll have to turn your sound system up, not insanely loud, but loud.
(I said that this would be the case before.) I can hear it, and I know
engineers who monitor much louder, routinely, than I’m monitoring to
hear this. My Equator Q10s are not terribly high powered, and I’m not
adding any other gain ahead of them in order to boost the quiet part.

If you want to hear the residual easily (32-bit version inverted, summed
with 16-bit truncated, the result with +40 dB gain via Trim plug-in):

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav


I don’t expect the 16-bit truncated version to bother you, but it does
bother some audio engineers. Here's 16-bit dithered version, for
completeness, so that you can decide if the added noise floor bothers you:

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav




On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:

Yes, I disagree with the "always". "Not always needed" means "it's
sometimes needed", my point is that it's never needed, until proven
otherwise. Your video proves that sometimes it's not needed, but not
that sometimes it's needed.



-Message d'origine- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 6:51 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles


I totally understood the point of your video, that dithering to 16bit
isn't always needed - but that's what I disagree with.


Sorry, Didier, I’m confused now. I took from your previous message
that you feel 16-bit doesn’t need to be dithered ("dithering to 16bit
will never make any audible difference”). Here you say that you
disagree with "dithering to 16bit isn't always needed”. In fact, you
are saying that it’s never needed—you disagree because “isn’t always
needed” implies that it is sometimes needed—correct?



On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:


Then, it’s no-win situation, because I could EASILY manufacture a
bit of music that had significant truncation distortion at 16-bit.


Please do, I would really like to hear it.

I have never heard truncation noise at 16bit, other than by playing
with levels in a such a way that the peaking parts of the rest of the
sound would destroy your ears or be very unpleasant at best. (you say
12dB, it's already a lot)

I totally understood the point of your video, that dithering to 16bit
isn't always needed - but that's what I disagree with.



-Message d'origine----- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 10:59 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Hi Didier—You seem to find contradictions in my choices because you
are making the wrong assumptions about what I’m showing and saying.

First, I’m not steadfast that 16-bit dither is always needed—and in
fact the point of the video was that I was showing you (the viewers)
how you can judge it objectively for yourself (and decide whether you
want to dither). This is a much better way that the usual that I hear
from people, who often listen to the dithered and non-dithered
results, and talk about the "soundstage collap

Re: [music-dsp] Dither video and articles

2015-02-05 Thread Andreas Beisler

The artifacts are very prominent in the tail end of the truncated file. 
I don't understand how you cannot hear it. Must be covered by the noise 
floor of your sound card's converters.


Andreas



On 2/5/2015 1:55 PM, Didier Dambrin wrote:

I couldn't hear any difference (through headphones), even after an
insane boost, and even though your 16bit truncated wav was 6dB(?) lower
than the 32bit wav

But even if I could hear it, IMHO this is 13bit worth of audio inside a
16bit file.




-Message d'origine- From: Nigel Redmon
Sent: Thursday, February 05, 2015 9:13 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

OK, here’s my new piece, I call it Diva bass—to satisfy your request for
me to make something with truncation distortion apparent. (If it bother
you that my piece is one note, imagine that this is just the last note
of a longer piece.)

I spent maybe 30 seconds getting the sound—opened Diva (default
“minimoog” modules), turn the mixer knobs down except for VCO 1, set
range to 32’, waveform to triangle, max release on the VCA envelope.

In 32-bit float glory:

http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav

Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer),
saved to 16-bit wave file:

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav

You’ll have to turn your sound system up, not insanely loud, but loud.
(I said that this would be the case before.) I can hear it, and I know
engineers who monitor much louder, routinely, than I’m monitoring to
hear this. My Equator Q10s are not terribly high powered, and I’m not
adding any other gain ahead of them in order to boost the quiet part.

If you want to hear the residual easily (32-bit version inverted, summed
with 16-bit truncated, the result with +40 dB gain via Trim plug-in):

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav


I don’t expect the 16-bit truncated version to bother you, but it does
bother some audio engineers. Here's 16-bit dithered version, for
completeness, so that you can decide if the added noise floor bothers you:

http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav




On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:

Yes, I disagree with the "always". "Not always needed" means "it's
sometimes needed", my point is that it's never needed, until proven
otherwise. Your video proves that sometimes it's not needed, but not
that sometimes it's needed.



-Message d'origine- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 6:51 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles


I totally understood the point of your video, that dithering to 16bit
isn't always needed - but that's what I disagree with.


Sorry, Didier, I’m confused now. I took from your previous message
that you feel 16-bit doesn’t need to be dithered ("dithering to 16bit
will never make any audible difference”). Here you say that you
disagree with "dithering to 16bit isn't always needed”. In fact, you
are saying that it’s never needed—you disagree because “isn’t always
needed” implies that it is sometimes needed—correct?



On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:


Then, it’s no-win situation, because I could EASILY manufacture a
bit of music that had significant truncation distortion at 16-bit.


Please do, I would really like to hear it.

I have never heard truncation noise at 16bit, other than by playing
with levels in a such a way that the peaking parts of the rest of the
sound would destroy your ears or be very unpleasant at best. (you say
12dB, it's already a lot)

I totally understood the point of your video, that dithering to 16bit
isn't always needed - but that's what I disagree with.



-Message d'origine----- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 10:59 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Hi Didier—You seem to find contradictions in my choices because you
are making the wrong assumptions about what I’m showing and saying.

First, I’m not steadfast that 16-bit dither is always needed—and in
fact the point of the video was that I was showing you (the viewers)
how you can judge it objectively for yourself (and decide whether you
want to dither). This is a much better way that the usual that I hear
from people, who often listen to the dithered and non-dithered
results, and talk about the "soundstage collapsing" without dither,
“brittle” versus “transparent" , etc.

But if I’m to give you a rule of thumb, a practical bit of advice
that you can apply without concern that you might be doing something
wrong in a given circumstance, that advice is “always dither 16-bit
reductions”. First, I suspect that i

Re: [music-dsp] Dither video and articles

I couldn't hear any difference (through headphones), even after an insane 
boost, and even though your 16bit truncated wav was 6dB(?) lower than the 
32bit wav


But even if I could hear it, IMHO this is 13bit worth of audio inside a 
16bit file.





-Message d'origine- 
From: Nigel Redmon

Sent: Thursday, February 05, 2015 9:13 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

OK, here’s my new piece, I call it Diva bass—to satisfy your request for me 
to make something with truncation distortion apparent. (If it bother you 
that my piece is one note, imagine that this is just the last note of a 
longer piece.)


I spent maybe 30 seconds getting the sound—opened Diva (default “minimoog” 
modules), turn the mixer knobs down except for VCO 1, set range to 32’, 
waveform to triangle, max release on the VCA envelope.


In 32-bit float glory:

http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav

Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), saved 
to 16-bit wave file:


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav

You’ll have to turn your sound system up, not insanely loud, but loud. (I 
said that this would be the case before.) I can hear it, and I know 
engineers who monitor much louder, routinely, than I’m monitoring to hear 
this. My Equator Q10s are not terribly high powered, and I’m not adding any 
other gain ahead of them in order to boost the quiet part.


If you want to hear the residual easily (32-bit version inverted, summed 
with 16-bit truncated, the result with +40 dB gain via Trim plug-in):


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav

I don’t expect the 16-bit truncated version to bother you, but it does 
bother some audio engineers. Here's 16-bit dithered version, for 
completeness, so that you can decide if the added noise floor bothers you:


http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav




On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:

Yes, I disagree with the "always". "Not always needed" means "it's 
sometimes needed", my point is that it's never needed, until proven 
otherwise. Your video proves that sometimes it's not needed, but not that 
sometimes it's needed.




-Message d'origine- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 6:51 PM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

I totally understood the point of your video, that dithering to 16bit 
isn't always needed - but that's what I disagree with.


Sorry, Didier, I’m confused now. I took from your previous message that 
you feel 16-bit doesn’t need to be dithered ("dithering to 16bit will 
never make any audible difference”). Here you say that you disagree with 
"dithering to 16bit isn't always needed”. In fact, you are saying that it’s 
never needed—you disagree because “isn’t always needed” implies that it is 
sometimes needed—correct?




On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:

Then, it’s no-win situation, because I could EASILY manufacture a bit 
of music that had significant truncation distortion at 16-bit.


Please do, I would really like to hear it.

I have never heard truncation noise at 16bit, other than by playing with 
levels in a such a way that the peaking parts of the rest of the sound 
would destroy your ears or be very unpleasant at best. (you say 12dB, 
it's already a lot)


I totally understood the point of your video, that dithering to 16bit 
isn't always needed - but that's what I disagree with.




-Message d'origine- From: Nigel Redmon
Sent: Wednesday, February 04, 2015 10:59 AM
To: A discussion list for music-related DSP
Subject: Re: [music-dsp] Dither video and articles

Hi Didier—You seem to find contradictions in my choices because you are 
making the wrong assumptions about what I’m showing and saying.


First, I’m not steadfast that 16-bit dither is always needed—and in fact 
the point of the video was that I was showing you (the viewers) how you 
can judge it objectively for yourself (and decide whether you want to 
dither). This is a much better way that the usual that I hear from 
people, who often listen to the dithered and non-dithered results, and 
talk about the "soundstage collapsing" without dither, “brittle” versus 
“transparent" , etc.


But if I’m to give you a rule of thumb, a practical bit of advice that 
you can apply without concern that you might be doing something wrong in 
a given circumstance, that advice is “always dither 16-bit reductions”. 
First, I suspect that it’s below the existing noise floor of most music 
(even so, things like slow fades of the master fader might override that, 
for that point in time). Still, it’s not hard to manufacture something 
m

Re: [music-dsp] Dither video and articles

Hmm, I thought that would let you save the page source (wave file)…Safari 
creates the file of the appropriate name and type, but it stays at 0 bytes…OK, 
I put up and index page—do the usual right-click to save the field to disk if 
you need to access the files directly:

http://earlevel.com/temp/music-dsp/


> On Feb 5, 2015, at 12:13 AM, Nigel Redmon  wrote:
> 
> OK, here’s my new piece, I call it Diva bass—to satisfy your request for me 
> to make something with truncation distortion apparent. (If it bother you that 
> my piece is one note, imagine that this is just the last note of a longer 
> piece.)
> 
> I spent maybe 30 seconds getting the sound—opened Diva (default “minimoog” 
> modules), turn the mixer knobs down except for VCO 1, set range to 32’, 
> waveform to triangle, max release on the VCA envelope.
> 
> In 32-bit float glory:
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2032-bit%20float.wav
> 
> Truncated to 16-bit, no dither (Quan Jr plug-in, Digital Performer), saved to 
> 16-bit wave file:
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated.wav
> 
> You’ll have to turn your sound system up, not insanely loud, but loud. (I 
> said that this would be the case before.) I can hear it, and I know engineers 
> who monitor much louder, routinely, than I’m monitoring to hear this. My 
> Equator Q10s are not terribly high powered, and I’m not adding any other gain 
> ahead of them in order to boost the quiet part.
> 
> If you want to hear the residual easily (32-bit version inverted, summed with 
> 16-bit truncated, the result with +40 dB gain via Trim plug-in):
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20truncated%20residual%20+40dB.wav
> 
> I don’t expect the 16-bit truncated version to bother you, but it does bother 
> some audio engineers. Here's 16-bit dithered version, for completeness, so 
> that you can decide if the added noise floor bothers you:
> 
> http://earlevel.com/temp/music-dsp/Diva%20bass%2016-bit%20dithered.wav
> 
> 
> 
>> On Feb 4, 2015, at 1:10 PM, Didier Dambrin  wrote:
>> 
>> Yes, I disagree with the "always". "Not always needed" means "it's sometimes 
>> needed", my point is that it's never needed, until proven otherwise. Your 
>> video proves that sometimes it's not needed, but not that sometimes it's 
>> needed.
>> 
>> 
>> 
>> -Message d'origine- From: Nigel Redmon
>> Sent: Wednesday, February 04, 2015 6:51 PM
>> To: A discussion list for music-related DSP
>> Subject: Re: [music-dsp] Dither video and articles
>> 
>>> I totally understood the point of your video, that dithering to 16bit isn't 
>>> always needed - but that's what I disagree with.
>> 
>> Sorry, Didier, I’m confused now. I took from your previous message that you 
>> feel 16-bit doesn’t need to be dithered ("dithering to 16bit will never make 
>> any audible difference”). Here you say that you disagree with "dithering to 
>> 16bit isn't always needed”. In fact, you are saying that it’s never 
>> needed—you disagree because “isn’t always needed” implies that it is 
>> sometimes needed—correct?
>> 
>> 
>>> On Feb 4, 2015, at 5:06 AM, Didier Dambrin  wrote:
>>> 
>>>>> Then, it’s no-win situation, because I could EASILY manufacture a bit of 
>>>>> music that had significant truncation distortion at 16-bit.
>>> 
>>> Please do, I would really like to hear it.
>>> 
>>> I have never heard truncation noise at 16bit, other than by playing with 
>>> levels in a such a way that the peaking parts of the rest of the sound 
>>> would destroy your ears or be very unpleasant at best. (you say 12dB, it's 
>>> already a lot)
>>> 
>>> I totally understood the point of your video, that dithering to 16bit isn't 
>>> always needed - but that's what I disagree with.
>>> 
>>> 
>>> 
>>> -Message d'origine- From: Nigel Redmon
>>> Sent: Wednesday, February 04, 2015 10:59 AM
>>> To: A discussion list for music-related DSP
>>> Subject: Re: [music-dsp] Dither video and articles
>>> 
>>> Hi Didier—You seem to find contradictions in my choices because you are 
>>> making the wrong assumptions about what I’m showing and saying.
>>> 
>>> First, I’m not steadfast that 16-bit dither is always needed—and in fact 
>>> the point of the video was that I was showing you (the viewers) how you can 
>>> judge it objectively for yourself (and decide whet

Re: [music-dsp] Dither video and articles