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44.1 vs 88.2 ABX report at AES
2Bdecided
post Jul 16 2010, 17:07
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Here:

http://www.aes.org/events/128/papers/?ID=2252

QUOTE
P18-6 Sampling Rate Discrimination: 44.1 kHz vs. 88.2 kHz—Amandine Pras, Catherine Guastavino, McGill University - Montreal, Quebec, Canada
It is currently common practice for sound engineers to record digital music using high-resolution formats, and then down sample the files to 44.1 kHz for commercial release. This study aims at investigating whether listeners can perceive differences between musical files recorded at 44.1 kHz and 88.2 kHz with the same analog chain and type of AD-converter. Sixteen expert listeners were asked to compare 3 versions (44.1 kHz, 88.2 kHz, and the 88.2 kHz version down-sampled to 44.1 kHz) of 5 musical excerpts in a blind ABX task. Overall, participants were able to discriminate between files recorded at 88.2 kHz and their 44.1 kHz down-sampled version. Furthermore, for the orchestral excerpt, they were able to discriminate between files recorded at 88.2 kHz and files recorded at 44.1 kHz.
Convention Paper 8101


Was anyone at the presentation? Has anyone bought the paper?

Cheers,
David.
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AndyH-ha
post Jul 17 2010, 09:55
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It seems that what I wrote in the first part of my post here has been addressed since I read the thread, but the second part still might bare consideration.

I’m not following the discussions about brick-wall filters since I am under the impression that the majority of modern audio converters are some version of delta-sigma, which does not use such filters. Actual sample rates are high, 64X and 128X being typical, with digital decimation being used to achieve the final sample rate and prevent aliasing. The front-end analogue filters are described at “rather mild,” far short of what would be required to prevent aliasing in an non-oversamplng design.

My main reference is copyright 2000 (Ken Pohlmann’s Principles of Digital Audio, 4th edition), so something might have changed in this regard recently, but I’ve never seen anything about it. Is the discussion about brick-wall filters aimed at a special market or do I have some basic misunderstanding on this topic?

I would also like to throw something more into the discussion. Maybe explicit recognition of it could lead to some way to account for it in the testing. I’ve written about it in two earlier threads. Possibly some of the links to screen shots still exist in one of those.

I generated a sweep frequency signal at 88.2kz, covering the entire available frequency range. Playing it out the DAC of one soundcard and into the ADC of another, I found that I got back something very close to what was initially generated in CoolEdit (except with a SB Live).

Then, playing it at 88.2 and recording at 44.1kHz, I found a definite alias image. For the first couple kHz below the Nyquist Limit, hen recording at 44.2kHz, the image was quite strong. If I turned up the resolution in CoolEdit’s Spectral View, I could see the alias trace almost to zero Hz. Resampling the generated sweep tone in CoolEdit from 88.22 to 44.1 produced none of the aliasing.

I tested several reputable sound cards. All were the same (except the SB, which was much worse). When I initially posted these results in another forum there was a lot of noise about my failures until a couple of people with more expensive professional converters duplicated my results. This happened again later in another forum. While this is still only a small sample of all soundcards, I suspect they all do the same.

As discussed earlier in HA, I don’t think this is a significant audio defect. Certainly I cannot hear any distortion that may be produced, especially at 20kHz and above. Very little music has much content at the higher frequencies necessary to produce such aliasing anyway, and any such hf is likely to be rather low in intensity.

Still, this does make for a real difference in recording at higher sample rates vs. 44.1kHz. Aliasing cannot be removed from the recording. Since the alias image is only very strong (relative to the input signal) for a couple of kHz below the Nyquist Limit (meaning about 42kHz to 44kHz at a sample rate of 88.2kHz), even the little distortion that might be present in 44.1kHz recordings will be absent at 2X that, and above.
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googlebot
post Jul 17 2010, 10:49
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AndyH-ha, that might be on purpose. For two lowpass filters of identical computational complexity, with A being allowed to inject more imaging above f than B, et ceteris paribus, A has potentially higher passband performance (0-f Hz) than B.

This post has been edited by googlebot: Jul 17 2010, 10:53
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Posts in this topic
- 2Bdecided   44.1 vs 88.2 ABX report at AES   Jul 16 2010, 17:07
- - Dologan   Interesting. The fact that the discrimination was ...   Jul 16 2010, 18:18
|- - C.R.Helmrich   http://coltrane.music.mcgill.ca/MAQ/experiments co...   Jul 16 2010, 19:33
|- - Dologan   QUOTE (C.R.Helmrich @ Jul 16 2010, 19:33)...   Jul 16 2010, 20:30
- - Arnold B. Krueger   QUOTE (2Bdecided @ Jul 16 2010, 12:07) He...   Jul 16 2010, 19:45
|- - pbelkner   QUOTE (Arnold B. Krueger @ Jul 16 2010, 20...   Jul 16 2010, 20:01
||- - Dologan   QUOTE (pbelkner @ Jul 16 2010, 20:01) QUO...   Jul 16 2010, 20:03
||- - pbelkner   QUOTE (Dologan @ Jul 16 2010, 21:03) but ...   Jul 16 2010, 20:19
||- - benski   Yes, exactly. It is cheaper to design a 192kHz DA...   Jul 16 2010, 20:47
||- - Arnold B. Krueger   QUOTE (Dologan @ Jul 16 2010, 15:03) QUOT...   Jul 16 2010, 23:21
|- - C.R.Helmrich   QUOTE Overall, participants were able to discrimin...   Jul 16 2010, 20:25
|- - pbelkner   QUOTE (C.R.Helmrich @ Jul 16 2010, 21:25)...   Jul 16 2010, 20:59
- - krabapple   1) I suggest this thread be focused on the 44.1 v...   Jul 16 2010, 22:23
|- - WernerO   QUOTE (krabapple @ Jul 16 2010, 23:23) Th...   Aug 11 2010, 13:51
|- - mzil   QUOTE (krabapple @ Jul 16 2010, 17:23) 2)...   Jul 22 2012, 02:47
|- - C.R.Helmrich   Sorry for bumping this thread, but I thought the f...   Mar 8 2014, 01:21
|- - [JAZ]   QUOTE (C.R.Helmrich @ Mar 8 2014, 01:21) ...   Mar 8 2014, 18:38
- - googlebot   Why upsample? 99.9% of all DACs oversample anyway....   Jul 16 2010, 22:25
|- - Arnold B. Krueger   QUOTE (googlebot @ Jul 16 2010, 17:25) Wh...   Jul 16 2010, 23:47
|- - benski   QUOTE (Arnold B. Krueger @ Jul 16 2010, 18...   Jul 17 2010, 03:12
||- - Arnold B. Krueger   QUOTE (benski @ Jul 16 2010, 22:12) QUOTE...   Jul 17 2010, 06:39
||- - greynol   QUOTE (Arnold B. Krueger @ Jul 16 2010, 22...   Jul 17 2010, 18:33
||- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 13:33) QUOT...   Jul 17 2010, 20:35
|- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 16 2010, 23...   Jul 21 2010, 13:22
- - Alex B   I think the least incorrect way to compare 88.2 KH...   Jul 16 2010, 22:33
|- - Arnold B. Krueger   QUOTE (Alex B @ Jul 16 2010, 17:33) I thi...   Jul 16 2010, 23:30
|- - Dologan   QUOTE (Alex B @ Jul 16 2010, 22:33) I thi...   Jul 16 2010, 23:40
- - AndyH-ha   It seems that what I wrote in the first part of my...   Jul 17 2010, 09:55
|- - googlebot   AndyH-ha, that might be on purpose. For two lowpas...   Jul 17 2010, 10:49
- - googlebot   I think the 88.2 vs. downsampled 44.1 test had at ...   Jul 17 2010, 16:39
- - greynol   QUOTE (Arnold B. Krueger @ Jul 17 2010, 12...   Jul 17 2010, 20:48
|- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 15:48) QUOT...   Jul 17 2010, 23:04
- - AndyH-ha   I also may not know what I'm talking about, bu...   Jul 17 2010, 22:02
- - greynol   The reason for oversampling in old CD players is a...   Jul 17 2010, 22:13
|- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 17:13) The ...   Jul 17 2010, 23:14
- - greynol   I'm taking issue with what I thought was a bla...   Jul 17 2010, 23:27
|- - Arnold B. Krueger   QUOTE (greynol @ Jul 17 2010, 18:27) I...   Jul 18 2010, 01:52
|- - greynol   QUOTE (Arnold B. Krueger @ Jul 17 2010, 17...   Jul 19 2010, 00:56
- - amandinepras   Thanks all for your interest in our paper, I recei...   Jul 19 2010, 00:52
|- - Arnold B. Krueger   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 19 2010, 03:35
|- - Arnold B. Krueger   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 19 2010, 11:35
||- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 19 2010, 11...   Jul 21 2010, 13:20
||- - Kees de Visser   QUOTE (2Bdecided @ Jul 21 2010, 14:20) QU...   Jul 23 2010, 09:26
|- - Arnold B. Krueger   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 19 2010, 11:48
||- - googlebot   QUOTE (Arnold B. Krueger @ Jul 19 2010, 12...   Jul 19 2010, 12:19
|||- - Arnold B. Krueger   QUOTE (googlebot @ Jul 19 2010, 07:19) QU...   Jul 19 2010, 14:33
||- - krabapple   QUOTE (Arnold B. Krueger @ Jul 19 2010, 06...   Jul 19 2010, 14:08
|- - Notat   QUOTE (amandinepras @ Jul 18 2010, 17:52)...   Jul 21 2010, 04:08
|- - hciman77   QUOTE (amandinepras @ Jul 18 2010, 19:52)...   Jul 28 2010, 15:18
- - Pio2001   Thanks for joining the discussion, Amandine. Your...   Jul 19 2010, 12:31
|- - 2Bdecided   QUOTE (Pio2001 @ Jul 19 2010, 12:31) I se...   Jul 21 2010, 13:13
- - googlebot   The study shows at least the intent of objectivity...   Jul 19 2010, 16:28
|- - Arnold B. Krueger   QUOTE (googlebot @ Jul 19 2010, 11:28) [l...   Jul 19 2010, 19:11
|- - Soap   QUOTE (Arnold B. Krueger @ Jul 19 2010, 14...   Jul 19 2010, 20:24
|- - Soap   QUOTE (Arnold B. Krueger @ Jul 19 2010, 14...   Jul 19 2010, 23:07
- - Juha   QUOTE Doesn't anybody else see a problem with ...   Jul 19 2010, 19:25
- - googlebot   The manufacturer's specs for the FF 800. Unwei...   Jul 19 2010, 20:22
|- - Arnold B. Krueger   QUOTE (googlebot @ Jul 19 2010, 15:22) Th...   Jul 19 2010, 21:26
- - Cavaille   Forgive me to interrupt this discussion about the ...   Jul 20 2010, 08:40
|- - Arnold B. Krueger   QUOTE (Cavaille @ Jul 20 2010, 03:40) Arn...   Jul 20 2010, 13:13
|- - Arnold B. Krueger   QUOTE (Arnold B. Krueger @ Jul 20 2010, 08...   Jul 20 2010, 19:30
||- - Pio2001   QUOTE (Arnold B. Krueger @ Jul 20 2010, 20...   Jul 20 2010, 22:36
|||- - Arnold B. Krueger   QUOTE (Pio2001 @ Jul 20 2010, 17:36) QUOT...   Jul 20 2010, 23:57
||- - C.R.Helmrich   QUOTE (Arnold B. Krueger @ Jul 20 2010, 20...   Jul 20 2010, 22:53
|- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 20 2010, 13...   Jul 21 2010, 13:25
|- - WernerO   QUOTE (Arnold B. Krueger @ Jul 20 2010, 14...   Aug 2 2010, 08:19
|- - Arnold B. Krueger   QUOTE (WernerO @ Aug 2 2010, 03:19) QUOTE...   Aug 2 2010, 11:56
- - Pio2001   The strange thing is that there are ABX results wi...   Jul 21 2010, 12:16
|- - hciman77   QUOTE (Pio2001 @ Jul 21 2010, 07:16) The ...   Jul 27 2010, 22:56
- - googlebot   The fact, that the study's authors have regist...   Jul 23 2010, 10:55
|- - Pio2001   QUOTE (googlebot @ Jul 23 2010, 11:55) co...   Jul 24 2010, 13:58
- - krabapple   Sheesh, it's only been four days. They may ac...   Jul 23 2010, 19:20
- - googlebot   In dubio pro reo is generally a good principle. Bu...   Jul 26 2010, 19:43
|- - hciman77   QUOTE (googlebot @ Jul 26 2010, 14:43) In...   Jul 26 2010, 21:05
- - hciman77   I read the full paper and I think there may be som...   Jul 26 2010, 19:48
|- - Arnold B. Krueger   QUOTE (hciman77 @ Jul 26 2010, 14:48) I r...   Jul 27 2010, 13:16
||- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jul 27 2010, 13...   Jul 27 2010, 22:45
|- - Pio2001   QUOTE (hciman77 @ Jul 26 2010, 20:48) Thi...   Jul 28 2010, 11:39
|- - Arnold B. Krueger   QUOTE (Pio2001 @ Jul 28 2010, 06:39) QUOT...   Jul 28 2010, 13:52
|- - AndyH-ha   QUOTE (Arnold B. Krueger @ Jul 28 2010, 04...   Jul 28 2010, 22:42
|- - Arnold B. Krueger   QUOTE (AndyH-ha @ Jul 28 2010, 17:42...   Jul 29 2010, 13:04
|- - 2Bdecided   QUOTE (AndyH-ha @ Jul 28 2010, 22:42...   Jul 29 2010, 22:11
|- - SebastianG   QUOTE (2Bdecided @ Jul 29 2010, 22:11) bu...   Jul 30 2010, 09:55
|- - Arnold B. Krueger   QUOTE (2Bdecided @ Jul 29 2010, 17:11) I ...   Jul 30 2010, 12:26
- - lvqcl   Audition 1.5: 44.1 -> 96 kHz resampling, Qualit...   Jul 30 2010, 11:42
- - C.R.Helmrich   I finally found time to read the entire paper. It...   Aug 9 2010, 21:41
- - 2Bdecided   I think before you pull out one positive result an...   Aug 9 2010, 22:44
|- - C.R.Helmrich   QUOTE (2Bdecided @ Aug 9 2010, 23:44) I t...   Aug 10 2010, 01:37
- - Pio2001   I finaly got the article. Actually, they say somet...   Aug 9 2010, 23:33
- - Pio2001   The unknown thing is the origin of the p values. I...   Aug 10 2010, 12:33
- - lrossouw   Did they test for difference (Check if you can tel...   Sep 8 2010, 09:39
- - Mach-X   I am going to loosely quote a well known poster he...   Mar 8 2014, 08:08
|- - Arnold B. Krueger   QUOTE (Mach-X @ Mar 8 2014, 03:08) I...   Mar 10 2014, 12:58
- - bandpass   TEAC -- slight COI perhaps? Guessing their method...   Mar 8 2014, 09:06
- - WernerO   Perhaps. Another weakness is their apparent use o...   Mar 11 2014, 08:04
|- - Arnold B. Krueger   QUOTE (WernerO @ Mar 11 2014, 03:04) Perh...   Mar 11 2014, 13:44
||- - Kees de Visser   QUOTE (Arnold B. Krueger @ Mar 11 2014, 13...   Mar 11 2014, 14:28
|- - C.R.Helmrich   QUOTE (WernerO @ Mar 11 2014, 08:04) Anot...   Mar 11 2014, 23:55
- - Wombat   QUOTE (Kees de Visser @ Mar 11 2014, 14:2...   Mar 11 2014, 15:51
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