Didier, I can hear hiss down at -72 dBFS while a 0 dBFS 440 hz sine wave is playing. There is no compressor in my signal chain anywhere, I use an RME FireFace UCX and have all gains to 0 dBFS and only adjust the headhpone out gain. The FX % cpu on the soundcard is at 0 %, and I even double checked through all the power buttons for the EQ / Comps on each channel, nothing is on.
I will not reply to you any further on this topic, I have made my statements very clear, posted examples, and been very patient with you, but you still don't want to believe me so it is best to not discuss it any further as it is just wasting everyone's time. All the best, Andrew -- cytomic -- sound music software -- On 10 February 2015 at 21:35, Didier Dambrin <di...@skynet.be> wrote: > > 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 <di...@skynet.be> 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 <di...@skynet.be> 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 <a...@cytomic.com> wrote: >>>> >>>> >>>> >>>> On 6 February 2015 at 17:32, Didier Dambrin <di...@skynet.be> 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 >>> >>> >>> >>> -- >>> 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 >>> >>> >>> ----- >>> Aucun virus trouve dans ce message. >>> Analyse effectuee par AVG - www.avg.fr >>> Version: 2015.0.5645 / Base de donnees virale: 4281/9068 - Date: >>> 06/02/2015 >>> -- >>> 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 >> >> >> ----- >> Aucun virus trouve dans ce message. >> Analyse effectuee par AVG - www.avg.fr >> Version: 2015.0.5645 / Base de donnees virale: 4281/9071 - Date: 07/02/2015 >> -- >> 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 > > > ----- > Aucun virus trouve dans ce message. > Analyse effectuee par AVG - www.avg.fr > Version: 2015.0.5645 / Base de donnees virale: 4281/9084 - Date: 09/02/2015 > -- > 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
