Wen X schrieb:
> well, at least if averaged with spectral energy density then you get some
> positive result. this means negative group delay occurs in suppressed
> bands.
It better do in musical applications, because when the true input envelope
strongly deviates from what the filter's operation
>> - however, using FT[th(t)]=j(FT[h(t)])', one can show that the
>> centroid of
>> time w.r.t. the impulse response equals the centroid of group delay
>> w.r.t.
>> frequency response.
> so, when h(t)<0, does that cause negative time to be averaged into the
> centroid calculation?
sorry for
On Mar 18, 2011, at 1:55 PM, Wen X wrote:
- when considering finite duration there is the uncertainty
principle, so
you always deal with a pack of frequencies rather than one
frequency, which
makes "latency" dependent on the content of that pack.
- however, using FT[th(t)]=j(FT[h(t)])', on
March 2011 14:45
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Frequency-dependent latency of a filter
I guess I see the whole thing a bit more naive. And without the actual
implementation details in mind. Yes, the implementation comprises of a
DFT and that means we're dealing with e
March 2011 14:45
To: music-dsp@music.columbia.edu
Subject: Re: [music-dsp] Frequency-dependent latency of a filter
I guess I see the whole thing a bit more naive. And without the actual
implementation details in mind. Yes, the implementation comprises of a
DFT and that means we're dealing w
I guess I see the whole thing a bit more naive. And without the actual
implementation details in mind. Yes, the implementation comprises of a
DFT and that means we're dealing with everlasting sinusoids. And that's
already a problem.
But I see it more like having a signal that his made of finit
> I did some informal tests and as far as I saw this is correct.
> But since groupdelay is the rate of change of the phase response, I
> would think that it doesn't really describe the actual
> frequency-dependent latency. But even if it did, it would only give you
> the average latency of your
>
> not necessarily. causality does *not* imply non-negative group
> delay. it does not even imply it for *average* group delay (unless
> maybe if you weight the average in such a way that, at frequencies of
> less gain, the group delay there does not contribute as much to the
> average
On Mar 17, 2011, at 8:05 PM, Andreas Beisler wrote:
Hi. Sorry, I messed up the subject of the thread.
that's whacha get fer using the digest form. that'll teach ya!
--
r b-j r...@audioimagination.com
"Imagination is more important than knowledge."
--
dupswapdrop -- th
Hi. Sorry, I messed up the subject of the thread.
my understanding is if different frequenices are delayed by different
*time* then you have dispersion. in this sense the group delay as a
function of frequency can be written as an average group delay
(non-negative if causal) plus a zero-mean ite
On Mar 17, 2011, at 2:27 PM, xue wen wrote:
Yes, but only if the filter has high (negative?) dispersion
at that
frequency.
i'm not sure what that means. my understanding of dispersion would
be
a rapid change of phase or delay vs. frequency.
my understanding is if different freq
>>
>> Yes, but only if the filter has high (negative?) dispersion at that
>> frequency.
> i'm not sure what that means. my understanding of dispersion would be
> a rapid change of phase or delay vs. frequency.
my understanding is if different frequenices are delayed by different *time*
th
On Mar 17, 2011, at 12:00 PM, Wen X wrote:
From: music-dsp-boun...@music.columbia.edu
[mailto:music-dsp-boun...@music.columbia.edu] On Behalf Of robert
bristow-johnson
well, even group delay is negative with the peaking filters, for
*some* frequencies.
Yes, but only if the filter ha
>From: music-dsp-boun...@music.columbia.edu
[mailto:music-dsp-boun...@music.columbia.edu] On Behalf Of robert
bristow-johnson
> well, even group delay is negative with the peaking filters, for
> *some* frequencies.
Yes, but only if the filter has high (negative?) dispersion at that
frequ
On Mar 17, 2011, at 9:21 AM, Wen X wrote:
As far as causality is concerned it's the *group* delay that should be
non-negative.
well, even group delay is negative with the peaking filters, for
*some* frequencies.
with group delay, there is no issue of phase unwrapping since the
phase del
-boun...@music.columbia.edu] On Behalf Of Andreas Beisler
Sent: 17 March 2011 12:33
To: music-dsp@music.columbia.edu
Subject: [music-dsp] Frequency-dependent latency of a filter
Hi. After having worked in the field of musicdsp quite some years, there
is still one mysterium left: phase shift. The actual
Hi. After having worked in the field of musicdsp quite some years, there
is still one mysterium left: phase shift. The actual task at hand is to
estimate the frequency-dependent latency of an LTI filter. For a bunch
of filters (i.e. butterworth LP) it works rather well by just calling
Matlab's
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