24-bit 192-kHz Music Downloads and why they make no sense

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combatentropy

Veteran
24/192 Music Downloads ...and why they make no sense, by Chris Montgomery of Xiph.Org, which maintains the open-source media formats Ogg, Theora, and FLAC.

For final distribution (not necessarily recording and mixing) 16-bit, 44.1 kHz gives you all the fidelity you can hear. The writer bases this on human-ear anatomy and double-blind tests. Even for recording, more than 48 kHz is overkill, although a higher bit depth, like 24, might be useful during mixing. Again, this is about the final distribution format that you give to listeners after all production is finished.
 
There is a small flaw in Monty's article...

If you download his "Sample 2: 1kHz tone at -105 dB (16 bit / 48kHz WAV)" file and try playing the file in an audio editor, you will see that your level meters will sit at -70 dB and NOT -105 dB, so there is no free lunch with the 16-bit audio format.

Also if you try boosting his "Sample 2" WAV file by 70 dB, you will hear a very noisy dithered 1 kHz tone that plays back at 0 dB.
 
Great find, thanks for sharing.

In any test where a listener can tell two choices apart via any means apart from listening, the results will usually be what the listener expected in advance; this is called confirmation bias and it's similar to the placebo effect. It means people 'hear' differences because of subconscious cues and preferences that have nothing to do with the audio, like preferring a more expensive (or more attractive) amplifier over a cheaper option.

The human brain is designed to notice patterns and differences, even where none exist. This tendency can't just be turned off when a person is asked to make objective decisions; it's completely subconscious. Nor can a bias be defeated by mere skepticism. Controlled experimentation shows that awareness of confirmation bias actually increases rather than decreases the effect! A test that doesn't carefully eliminate confirmation bias is worthless.

In single-blind testing, a listener knows nothing in advance about the test choices, and receives no feedback during the course of the test. Single-blind testing is better than casual comparison, but it does not eliminate the experimenter's bias. The test administrator can easily inadvertently influence the test or transfer his own subconscious bias to the listener through inadvertent cues (eg, "Are you sure that's what you're hearing?", body language indicating a 'wrong' choice, hesitating inadvertently, etc). An experimenter's bias has also been experimentally proven to influence a test subject's results.

Double-blind listening tests are the gold standard; in these tests neither the test administrator nor the testee have any knowledge of the test contents or ongoing results. Computer-run ABX tests are the most famous example, and there are freely available tools for performing ABX tests on your own computer[14]. ABX is considered a minimum bar for a listening test to be meaningful; reputable audio forums such as Hydrogen Audio often do not even allow discussion of listening results unless they meet this minimum objectivity requirement [15].
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I think the same rules apply to 4k projection.
 
TheDingo said:
There is a small flaw in Monty's article...

If you download his "Sample 2: 1kHz tone at -105 dB (16 bit / 48kHz WAV)" file and try playing the file in an audio editor, you will see that your level meters will sit at -70 dB and NOT -105 dB, so there is no free lunch with the 16-bit audio format.

Also if you try boosting his "Sample 2" WAV file by 70 dB, you will hear a very noisy dithered 1 kHz tone that plays back at 0 dB.
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I suggest you actually forward these findings to the author, monty@xiph.org. He is pretty technical. He created the Ogg container format, Vorbis audio codec, and others (http://en.wikipedia.org/wiki/Chris_Montgomery). I suspect that if he had exported it differently then you would not have this problem.
 
There is no purpose in that high of a fidelity in music playback, but I'm all for recording at that resolution. It's not like disk space is exactly at a premium these days, and the more data the better. I plan for the future. I may take a piece of music I recorded at 24/192 and take a snippet of it and use it for a totally different purpose, such as sound design, and if I time expand like crazy, a lower resolution file is going to give me time expansion artifacts much sooner than a higher resolution file. But, purely for listening purposes, anyone that says they can tell the difference between the two different resolutions in question is most likely trying to impress you. What really matters is the quality of your speakers. I thought I had nice speakers on my stereo system until I went to my brother-in-law's house. He has a pair of B&K speakers that were about $15K for a pair. HUGE difference. I heard things I had never heard before on those speakers on music that I knew intimately.
 
My speakers were $1k a pair and I can hear a HUGE difference from consumer speakers (Adam A7s). I record at 48/24 and couldn't be happier with my results :)
 
Rick Burnett said:
My speakers were $1k a pair and I can hear a HUGE difference from consumer speakers (Adam A7s). I record at 48/24 and couldn't be happier with my results :)
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Yes, better speakers are a wiser investment.

Recording at 24-bit, 48 kHz makes the most sense to me, too. One thing I learned from the article is that the 192 kHz actually could make it worse, although slightly, due to ultrasonic distortion. Bottom line, a higher sampling rate ain't worth it.

Another thing to keep in mind is that he isn't talking about compression. I, for one, would welcome uncompressed files, like FLAC, over MP3's or whatever. At least that would be a better use of disk space than jacking up the sample rate.
 
TheDingo said:
There is a small flaw in Monty's article...

If you download his "Sample 2: 1kHz tone at -105 dB (16 bit / 48kHz WAV)" file and try playing the file in an audio editor, you will see that your level meters will sit at -70 dB and NOT -105 dB, so there is no free lunch with the 16-bit audio format.

Also if you try boosting his "Sample 2" WAV file by 70 dB, you will hear a very noisy dithered 1 kHz tone that plays back at 0 dB.
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I could be wrong, but I think the article is dancing around between digital and analog worlds. I THINK that the -105dB example was an analog -105dB, and he's trying to say that due to all the spectral effects and dithering, a 16-bit recording calibrated so that 0dB analog was 0dB digital could still capture SOMETHING of the -105dB analog audio.
 
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Rick Burnett said:
My speakers were $1k a pair and I can hear a HUGE difference from consumer speakers (Adam A7s). I record at 48/24 and couldn't be happier with my results :)
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It has always been the case that money invested in the transducers (microphones at one end, and speakers/headphones at the other end) have provided much more for your money than the equivalent in electronics or software.
 
When I got the Adam A7s, I was blown away. In fact, I had all my friends come over and listen to them as well so they could hear what a good monitor sounded like, because I certainly hadn't, or at least, not at this price point. Genelec's were the only other speaker that really impressed me.

Same thing just happened as I just received my Ultrasone Pro 750 headphones. I thought one of the drivers wasn't working listening to a Peter Gabriel track until I realized, the stereo separation was actually that much and I never realized it before :) (And of course all the other instruments kicked in to let me know both drivers were working).

I've done test after test with 16/24 bit and 44.1/48/96/192 kHz and the one thing I noticed is that converter noise sounded different, but I could never quantify better. When I do special effects stuff where I am slowing material WAY down, the 96/192 makes sense, but outside of that, I can't tell a difference.

Of course, I always add the caveat that maybe my ears aren't as good and I don't hear the difference. :)
 
I would say it depends on the quality of your playback system and what you listen to. On a tweek high end system with live orchestral material in a good hall, the ambient acoustics come through much better at higher encoding rates. But 48/24 is certainly going to get you 99% of the way there. 44.1/16 has never been satisfactory for serious acoustic music hobbyists.
 
Razz16mm said:
44.1/16 has never been satisfactory for serious acoustic music hobbyists.
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I can't avoid thinking how impressed the audio pioneers would have been with even 44.1/16 Or even how much better it is than the gear available when many of us started recording audio. As a high-school kid I bought myself a Sony TC-250 1/4 track recorder and three ECM-22 mics. Alas, the electret elements in the mics have long since gone flat and the mics are deaf as a post. Although my Sony C-37A mics are still a minor classic.
 
combatentropy said:
I suggest you actually forward these findings to the author, monty@xiph.org.
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Actually I did, but no reply so far.

I also did my own test where I took monty's Sample 1 WAV file which was a 1 kHz tone at 0 dB, converted it to 24-bit, then reduced the volume by 105 dB, and the finished file showed a volume level of -105 dB when played.

Next I took the -105 dB 24-bit file I had created and converted it to 16-bit using Gaussian dithering with Sony Sound Forge, and this new file showed a volume level of -84 dB. I was expecting to see the 1 kHz tone disappear, but Sound Forge boosted it to preserve it, which is kind of odd.
 
Razz16mm said:
I would say it depends on the quality of your playback system and what you listen to. On a tweek high end system with live orchestral material in a good hall, the ambient acoustics come through much better at higher encoding rates. But 48/24 is certainly going to get you 99% of the way there. 44.1/16 has never been satisfactory for serious acoustic music hobbyists.
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Did you even read the article?
 
Razz16mm said:
44.1/16 has never been satisfactory for serious acoustic music hobbyists.
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That is probably true but it also doesn't mean much. I helped a "serious acoustic music hobbyist" replace a bunch of speaker cable because he was convinced he could hear the difference between his already extremely thick copper cables and the new super thick "ultra copper" cables.

After spending $150 on cables he sure enough could clearly hear the difference. Since his listening position of choice was sitting on the floor surrounded with about 5,000 magazines and books even if the cables had made a difference he wouldn't have been able to tell.

He also had all the speaker cables balanced on styrofoam cups so they wouldn't touch the carpet because that "definitely" changed the sound.

44.1/16 got a bad reputation because originally the converters in CD players were, well, crap. And digital mastering was not all that polished.

Those same audiophiles ran out and got DolbyDigital surround systems for their "home theatres". DD is 44.1/16 and encoded in a flavor of MP3.

But this is a film sound list so... delivery is 48/16 for video. If your on a Mix stage doing a DD master your still probably running everything editorialy at 48/24 and converting down to 44.1/16 for the DD master.

Higher than that can be argued for acquisition but not strongly for working and they aren't used for delivery... yet.
 
Hehe, my favorite wrench for audiophiles:

"Yeah, but your copper wires in the wall, and the breaker in the electrical box, and the wire attached to your house to the pole, are they special?"

Seeing someone spend $500 on an electrical cord for their pre-amp was the ultimate for me. :)
 
Have you seen these? http://www.essentialsound.com/essence-power-cord/index.htm

They definitely make a difference to the sound when I listen to a system that uses them... it adds a sort of quiet quiet snickering, and the -163dB sound of eyes rolling. I like the fact that the endorsements imply that the sonic improvements might not be heard immediately so much as after a period of "breaking in."
 
ullanta said:
Have you seen these? http://www.essentialsound.com/essence-power-cord/index.htm

They definitely make a difference to the sound when I listen to a system that uses them... it adds a sort of quiet quiet snickering, and the -163dB sound of eyes rolling. I like the fact that the endorsements imply that the sonic improvements might not be heard immediately so much as after a period of "breaking in."
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Yes!!! Hahaha.

I want a large box that sits on top of my amp with a wire coming out of it and a label that says "Special Audio Style Electrons" that I feed into it. The electrons have been polished to provide better recreation of highs and a stiffer bottom end :)
 
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