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16bit vs 24bit, Rubbish or Truth?
Bourne
post Mar 27 2007, 04:02
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This post has been edited by Bourne: Apr 2 2008, 19:26
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AndyH-ha
post Jul 7 2008, 05:55
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Aside from the fact that it is almost always easy to tell live from a recording, no matter how good the recording, comparison of live vs recording of any particular bit depth is not only unnecessary, it is completely irrelevant to the question of whether there is any audible difference between a 24 bit recording and the same properly converted to 16 bits.

The question is simply can anyone actually tell the difference, merely by listening -- when they have no information except what they hear to tell them which is which. We are not talking about difference in equipment or listening environment, these have to be identical while listening to both versions. We can certainly consider the question of how good the equipment and environment need to be to allow a difference to be perceived, if such perception is possible, but that is not the issue itself.

The claim that only raw 24 bit recordings are clearly different is an interesting one. Just why a difference, audible when recorded at 24 bits, would disappear once the tracks are mixed, etc. (still at 24 bit) is unclear, unless you are talking about the mistreatment most pop and rock music is subjected to on it way from recording to distribution. Quite a few people have pointed out that SACD and DVD-A releases sometimes receive mastering that makes them better, and clearly distinguishable from, the CD version of the same recording. However, as the tests in the paper demonstrated, those differences are not lost or altered when that SACD/DVD-A recording is converted to CD specs.

For five years or so, whenever this subject comes up, in this and a number of other audio oriented forums, I have issued the challenge for anyone championing >16 bits and/or >44.1kHz, to provide a sample: something I can convert or resample (properly) and then identify in a correctly done blind ABX test. Only a real music recording is applicable; it isnít as hard to make up a sample with test tones.

I donít say that such recordings do not exist, only that I, and at least most of the other people on the planet, have yet to hear one. So far, every time Iíve made this request, the people arguing in favor of greater bit depth and/or sample rate have just gone away. (There is one thread, in this forum, where a poster claimed to be able to ABX just about any change whatsoever to some 24/96 samples, but I donít believe anyone else heard what he claimed to hear. (There were also some questions raised about his equipment) The thread got so convoluted that I stopped following it, but I donít think he convinced anyone.) (Also, that was just about sample rates, not bit depths).

Now I acknowledge that my inability to hear a difference, should a test file become available, does not mean no audible difference exists. The sample has to be available for wide ABX testing, to find out if everyone is as deaf as me. Many people who visit this forum are experienced in doing ABX testing.

Three to ten seconds should be adequate, I see no need for an entire track, but will consider any reasoned argument as to why a greater duration might be necessary to reveal a difference. My preference is for 24/44.1 since even a few seconds of audio is tedious to download over my dial-up line, but a restriction to CD spec sampling rate isnít a requirement. I, and probably most people, can handle 48kHz, 88.2kHz and 96kHz.

This post has been edited by AndyH-ha: Jul 7 2008, 06:00
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ccryder
post Jul 7 2008, 08:13
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QUOTE (AndyH-ha @ Jul 6 2008, 23:55) *
Aside from the fact that it is almost always easy to tell live from a recording, no matter how good the recording, comparison of live vs recording of any particular bit depth is not only unnecessary, it is completely irrelevant to the question of whether there is any audible difference between a 24 bit recording and the same properly converted to 16 bits.


Two points to make on this.
#1, if you don't know what you're supposed to be able to hear in that recording, i.e. if you don't have a live source (or preferably a live analog source without the A/D stage) to compare to the two recordings (consider what I'm talking about to be not an ABX comparison, but rather an ABX-C comparison, where C is the live analog source), then it changes your perception of what kinds of differences to expect from the outset. It's been my experience that different kinds of music, with different harmonic and reverberant content will have an effect on how drastic the differences between 16 and 24 bit will end up being. I start with the premise that the most valid test should be to determine which one produces a better sounding facsimile of the original. I maintain that without a reference to a live source... without a glimpse of what should be possible to hear in that passage, your brain may have nothing specific to look for when you're then tasked to look for differences between A&B. However, (for instance) if you know how much reverberant content the original source contained, I propose that would educate your ear for that particular test, and would change outcome of such a test.

#2, take 2 recordings, both recorded conservatively so as not to risk ever clipping or hitting 0dBFS for more than 1 sample. Say, -24dBFS is the highest peak on a simultaneouly recorded 24bit and 16bit recording. I don't care how much dither and noise shaping you add, you're not going to end up with more than 12 significant bits on a 16 bit recording, but with good quality analog components & A/D, you will still end up with 16 significant bits of audio on the 24bit version. The difference in listening back is effectively the difference between a 12bit recording and a 16 bit recording (noise floors notwithstanding). Can you hear that difference? Do you understand why you might hear that difference? Now, take an instance where there's one transient spike +12dB higher than the rest of the recorded music, and you happen to know exactly when (in advance) that spike will occur. So knowing that, and not wanting to ride the record levels to as to manually compress dynamic range, you leave the levels set in such a way that the majority of the peaks are at -12dBFS, and you allow room for that one spike to take it a fraction under 0dBFS. The majority of that recording in the 16 bit realm is still getting a "14bit treatment", and even then only at its loudest point that it gets that amount of resoution . And what about that 24-bit version? Still gets a full 16 bits or more of significant dynamic range. Think you can hear that difference? I'll make the bet again and again that any decent audio engineer can tell the difference between a 16bit recording and a 12-14 bit recording. And therein lies the reason a live, unmastered, unadulterated 24bit recording will, more often than not, be obviously better sounding than its 16bit counterpart.

I should say after reading recent posts (and even before reading them), that I agree with about 95% of the sentiment that higher sampling rates are largely indiscernible. I think it is possible that there are special situations when it might be possible to reliably discern the difference between 24/44.1 and 24/96.... but I would probably limit such situations to where a single acoustic instrument containing high frequency harmonic was being captured with *near coincident* stereo mic patterns like ORTF. It would be that type of situation that I would seriously doubt ever entered into the test equation performed by Moran and Co. Asked if I bother with 96kHz, I would tell you that only if I cared very deeply about the recording for my own personal music, or was being paid specifically for a 24/96kHZ, would I use 96kHz to record.
The rest gets the 48kHz treatment. Generally speaking, for mastered, fully produced music, I agree that 96kHz for playback is pretty much a waste of space and CPU power. Not having read Moran & Co.'s paper, but from the articles mentioned above, it would appear to me that the general focus of the test was to prove that higher sampling rates are a waste, and not greater wordlengths. Like I said, most of the time, and for the overwhelming majority of both listeners and listening material, I agree with their findings.

However, wordlength is an entirely different matter.
Bottom line: I believe unmastered 24-bit audio compared with unmastered 16-bit audio from the same source has the potential to indicate vast audible differences in the timbre and decay of both harmonic and fundamental content (as well as reverberant content) over time. Most people don't prefer to listen to unmastered, yet well captured recordings. However, there are some that do, like me, and given what I've mentioned above, for those people, it's night and day. However, crush the crap out of the 24bit recording, and master it to 16 bits with noise shaping and dither, and then compare the two, and you probably won't hear much of a difference.

Back when I did a lot of concert recordings (in those cases, unpaid jobs), there were many times I, being the only one using 24-bit technology at those venues, created a decent sounding recording, while everyone with 16bit technology ended up with noisy rubbish, solely because the majority of the content was far below -0dBFS.

There are a whole host of live, unmastered 24bit recordings on archive.org (of varying qualities based upon mic placement from the source, mic patterns, analog stages, and A/D stages).... some of which I personally recorded, and have been available publicly for the past 6 years or more. Anyone who wanted to do a test for themselves to hear the difference (provided they had playback capability with enough dynamic range) can pull down one of those recordings and do their own experiments. I suspect that most who say they don't hear a difference never tried to listen to this kind of source material.

So for anyone who prefers this kind of listening to the nightmare creations of audio engineers designed specifically to sell more records, there is no argument.
Anyone's perception of the value of 24bit recording *and listening* is simply a matter of perspective and expectations.

I recognize that the majority here doesn't listen that way, or to that kind of music, but I just thought perhaps a glimpse of thinking outside the box might put the argument of 16bit vs 24bit into better perspective, for both recording, and listening. Minimally, any argument in that vain needs to be first qualified by the type of source material and listening attitude of the participants.

-DH
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Posts in this topic
- Bourne   16bit vs 24bit   Mar 27 2007, 04:02
- - DigitalMan   Hmm, very long article. Seems to be a collection ...   Mar 27 2007, 04:20
- - Bourne   the very topic of the link... he is claiming that...   Mar 27 2007, 04:25
- - greynol   This has been covered to death on this forum alrea...   Mar 27 2007, 09:56
- - 2Bdecided   It's a load of pseudo science. The guy has a h...   Mar 27 2007, 10:00
|- - ccryder   QUOTE (2Bdecided @ Mar 27 2007, 04:00) It...   Jul 5 2008, 07:31
|- - Canar   QUOTE (ccryder @ Jul 4 2008, 23:31) Belie...   Jul 5 2008, 19:11
- - Bourne   @greynol I'm not starting a topic on that sub...   Mar 27 2007, 23:31
|- - Woodinville   QUOTE (Bourne @ Mar 27 2007, 15:31) @grey...   Mar 28 2007, 20:45
|- - chelgrian   QUOTE (Bourne @ Mar 27 2007, 23:31) I...   Mar 28 2007, 21:23
- - benski   It appears the site (and the article) are oriented...   Mar 28 2007, 22:08
- - 2Bdecided   Hang on a second benski, There's no argument ...   Mar 29 2007, 11:48
- - Filburt   Hmm, I just skimmed the first part, but the argume...   Mar 29 2007, 20:51
- - AndyH-ha   Who, believing in the gods, and their work in the...   Mar 29 2007, 21:02
- - Pandabear   Bourne - everyone's ears develop at their own ...   Mar 30 2007, 03:12
|- - pdq   QUOTE (Pandabear @ Mar 29 2007, 22:12) No...   Mar 30 2007, 15:45
|- - Synthetic Soul   QUOTE (Pandabear @ Mar 30 2007, 02:12) No...   Mar 30 2007, 16:43
- - AndyH-ha   I suspect most of us who visit here are capable of...   Mar 30 2007, 05:49
- - pdq   Let's see, I could believe David Robinson, or ...   Jul 5 2008, 15:52
|- - krabapple   QUOTE (pdq @ Jul 5 2008, 10:52) Let's...   Jul 7 2008, 18:41
- - Mike Giacomelli   I was curious what got Dan Heend so upset after al...   Jul 5 2008, 16:07
- - pdq   "A passage that is 6dB louder than another pa...   Jul 5 2008, 16:22
|- - Mike Giacomelli   QUOTE (pdq @ Jul 5 2008, 11:22) "A p...   Jul 5 2008, 16:31
||- - pdq   QUOTE (Mike Giacomelli @ Jul 5 2008, 11:3...   Jul 5 2008, 16:35
|- - ccryder   QUOTE (pdq @ Jul 5 2008, 10:22) "A p...   Jul 6 2008, 09:04
|- - SebastianG   QUOTE (ccryder @ Jul 6 2008, 10:04) http:...   Jul 6 2008, 11:17
||- - MichaelW   Cursed are the peacemakers, for they shall be beat...   Jul 6 2008, 12:11
|- - pdq   QUOTE (ccryder @ Jul 6 2008, 04:04) QUOTE...   Jul 6 2008, 12:21
- - sld   So it IS possible for people who get their Theory ...   Jul 5 2008, 17:56
|- - [JAZ]   QUOTE (sld @ Jul 5 2008, 18:56) So it IS ...   Jul 5 2008, 19:12
|- - ccryder   QUOTE ' date='Jul 5 2008, 13:12' post=...   Jul 6 2008, 10:43
|- - MLXXX   QUOTE (ccryder @ Jul 6 2008, 19:43) Might...   Jul 6 2008, 12:50
||- - ccryder   QUOTE (MLXXX @ Jul 6 2008, 06:50) QUOTE (...   Jul 6 2008, 13:35
|- - Mike Giacomelli   QUOTE (ccryder @ Jul 6 2008, 05:43) Regar...   Jul 6 2008, 17:05
- - AndyH-ha   QUOTE One might get a greater appreciation for wha...   Jul 6 2008, 20:23
- - Roseval   The question of sampling rate and bit depth are a ...   Jul 6 2008, 21:11
|- - ccryder   QUOTE (Roseval @ Jul 6 2008, 15:11) The q...   Jul 6 2008, 23:19
|- - Dynamic   Edit: I started typing this before ccryder's r...   Jul 7 2008, 00:34
- - hellokeith   QUOTE (ccryder @ Jul 6 2008, 17:19) There...   Jul 7 2008, 01:49
- - AndyH-ha   Aside from the fact that it is almost always easy ...   Jul 7 2008, 05:55
|- - ccryder   QUOTE (AndyH-ha @ Jul 6 2008, 23:55)...   Jul 7 2008, 08:13
|- - MichaelW   QUOTE (ccryder @ Jul 7 2008, 20:13) #2, t...   Jul 7 2008, 10:38
||- - ccryder   QUOTE (MichaelW @ Jul 7 2008, 04:38) QUOT...   Jul 7 2008, 11:58
|- - krabapple   QUOTE (ccryder @ Jul 7 2008, 03:13) The r...   Jul 7 2008, 18:51
|- - euphonic   QUOTE (ccryder @ Jul 7 2008, 00:13) #2, t...   Jul 7 2008, 23:56
|- - ccryder   OK, Gonna try once more to get some of you to unde...   Jul 8 2008, 05:31
||- - krabapple   QUOTE (ccryder @ Jul 8 2008, 00:31) Is my...   Jul 8 2008, 17:29
|- - ccryder   QUOTE (euphonic @ Jul 7 2008, 17:56) This...   Jul 8 2008, 05:46
|- - ccryder   The actual realized signal to noise ratio of the r...   Jul 8 2008, 06:27
|- - Nick.C   QUOTE (ccryder @ Jul 8 2008, 05:46) Reall...   Jul 8 2008, 07:54
|- - knutinh   QUOTE (ccryder @ Jul 8 2008, 06:46) QUOTE...   Jul 8 2008, 09:27
- - cabbagerat   QUOTE (ccryder @ Jul 6 2008, 14:19) a) ...   Jul 7 2008, 08:05
|- - ccryder   QUOTE (cabbagerat @ Jul 7 2008, 02:05) QU...   Jul 7 2008, 08:51
|- - SebastianG   QUOTE (ccryder @ Jul 7 2008, 09:51) That ...   Jul 7 2008, 10:14
|- - ccryder   I never said a word about dither in my last post. ...   Jul 7 2008, 11:47
|- - SebastianG   QUOTE (ccryder @ Jul 7 2008, 12:47) I nev...   Jul 7 2008, 13:15
- - AndyH-ha   Expectation and belief can, and have repeatedly be...   Jul 7 2008, 12:24
- - AndyH-ha   There is a lot of (mostly one-sided) talk about ra...   Jul 7 2008, 22:31
- - SebastianG   QUOTE Simply put, just about every noise shaping a...   Jul 8 2008, 09:49
- - MLXXX   QUOTE (ccryder @ Jul 8 2008, 14:31) Botto...   Jul 8 2008, 13:50
- - AndyH-ha   ďproperly noise shaped ditherĒ (what I wrote) is n...   Jul 9 2008, 12:42
|- - SebastianG   Hi Andy! QUOTE (AndyH-ha @ Jul 9 20...   Jul 9 2008, 14:07
- - AndyH-ha   Here is my ignorance showing. How does one ďbit sh...   Jul 9 2008, 22:08
- - Nick.C   If a signal with an amplitude of less than or equa...   Jul 9 2008, 22:12
|- - MichaelW   QUOTE (Nick.C @ Jul 10 2008, 10:12) If a ...   Jul 10 2008, 07:16
|- - Nick.C   QUOTE (MichaelW @ Jul 10 2008, 07:16) Doe...   Jul 10 2008, 08:00
- - Chromatix   Let's inject some common sense in to this, sha...   Jul 10 2008, 13:52
|- - SebastianG   QUOTE (Chromatix @ Jul 10 2008, 14:52) .....   Jul 10 2008, 15:47
- - Axon   Just to throw another log on the fire: My phono pr...   Jul 10 2008, 16:52
|- - Canar   QUOTE (Axon @ Jul 10 2008, 08:52) Just to...   Jul 10 2008, 17:12
|- - pdq   QUOTE (Axon @ Jul 10 2008, 11:52) Just to...   Jul 10 2008, 17:28
- - Axon   About 10, but still.   Jul 10 2008, 17:33
- - hellokeith   QUOTE (Chromatix @ Jul 10 2008, 07:52) I ...   Jul 10 2008, 19:25
- - greynol   C'mon now. This can be handled via PM. Let...   Jul 10 2008, 19:30
- - cabbagerat   QUOTE (hellokeith @ Jul 10 2008, 10:25) H...   Jul 10 2008, 21:08
- - Chromatix   Those in-car numbers look vaguely sensible to me. ...   Jul 11 2008, 11:31
- - 2Bdecided   The very best psychoacoustic experiments aim for 2...   Jul 14 2008, 16:07


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