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24-bit/192kHz music downloads and why they make no sense (2012)

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Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#161
post #124

Earlier quoted context omitted.

Decades ago, I was treated to an ABX test in my brother's recording studio. I easily recognized and preferred a 24/192 master he played versus the 16/44.1 down-mix. I honestly don't know whether there was something wrong with the down-mix, but qualitatively it did feel like it was "muffled" and coming from speakers, while the master really felt like live performance. He was surprised that I could tell them apart. I a…

This is an extremely hard comparison to do well. I'll give a few examples as to why: Small differences in gain are ABX able much more readily than differences in noise at the 16 vs 24 bit level. So if the signal chain gives even a small difference in gain between the samples that's what you'll track. A reasonable conversion path to 16 bits for mastering will also apply dithering and some kind of brickwall limiting (y…

> Small differences in gain are ABX able much more readily than differences in noise at the 16 vs 24 bit level.

This was common knowledge at least as far back as the mid 80s, when every hifi shop and salesguy knew to ensure the bit of gear with the highest profit margin got played an almost imperceptible bit louder than the gear the customer came in to buy during back to back testing.

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#162

Earlier quoted context omitted.

> Realistically, frequencies around 20 kHz will create audible artifacts (aliasing) The energy of the signal components above the Nyquist is generally very low, and very few double blind tests have given any indication that humans can detect the resulting aliasing (even though many people claim to be able to do, almost always in non-double-blind environments). Badly written digital synthesis can generate high energy…

Genereally very low for a single track? What about 200 tracks? Badly written synthesis, or badly recorded live instruments, or bounced and re-bounced dozens of times... we are not talking about the quality-defining aspect here. You can produce an excellent mix on KRKs connected directly to a MacBook. This space is not driven by a single precise formula. 48/96 kHz helps some engineers to produce better sounding mixes.…

If you recorded 200 tracks of the same instrument, so that the partials above Nyquist were all broadly the same, then sure, summing the tracks would include summing 200 copies of the aliasing results too.

But very little music is like that, and the energy profile above Nyquist will differ dramatically. Consequently, you're not summing a set of identical aliasing results, and in general, the results will still be undetectable to almost everyone.

Jacob Collier routinely works with 300+ tracks in Logic. He doesn't worry about this sort of thing, and neither do the Grammy voters who love what he does.

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#163

The OP is a bit off with their description of why pro audio engineers work in higher bit rates and sample rates. We use 24bit to preserve low level sounds eg reverb, breaths etc and use 32bit float when recording as the headroom is so massive clipping is not an issue (other than of course still neeing to avoid overloading microphones with max SPL - cleanly recorded distorted sound is still a fail). Unclipping 32bit f…

Have you ever actually checked the number of actual bits your ADC can use? Most 24 bit converters struggle to get to 18 bits. Nobody uses 32 bit float for recording (to do so is just to capture at least 10 bits of noise, most of that being brownian); its strictly a format for mixing and processing. You don't get any more resolution from 32 bit floating point than you do from 24 bit integer formats, but the result of…

"Nobody uses 32 bit float for recording" - you are just displaying total ignorance here.

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#164
post #146

Earlier quoted context omitted.

> Nobody uses 32 bit float for recording Yes they do, almost all high end field recorders used for film work are 32-bits now and have been for much of the last decade, often with some fancy preamp integration so that there is no expertise required for gain staging the recording. (I believe the implementations use a second matched 24bit ADC with 48 dB less gain in front of it). The result obviously doesn't have a nois…

There are precisely zero 32 bit ADCs in existence. There are ADCs that will provide 32 bits per sample but that's entirely different. Current technology limits the bit depth to 18-22 bits and going beyond that you'd be very quickly recording brownian (atomic) noise anyway. The point about 32 bit float is that it is a useful format for mixing, editing and general processing, so it is widely used in digital audio tools…

I didn't say anything about DACs! I'm correcting a specific claim you made

> Nobody uses 32 bit float for recording (to do so is just to capture at least 10 bits of noise, most of that being brownian);

This is not true and not true for a good and important reason! One which has no bearing on the kind of DACs that exist.

Modern field recorders allow gains set a 'reasonable' level that maximizes SNR for recordings but still won't clip when there are much louder peaks. Not so dissimilar to how a 6-digit multimeter can achieve its advertised performance both on a 0-5v range and a 0-300v range but cannot give more than 6 digits at the higher range.

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#165
post #41

Earlier quoted context omitted.

A treated room would be the most impactful, DACs the least.

The DAC is pretty impactful if it's outright incapable of outputting anything beyond the usual 48kHz :)

Even the cheapest consumer DACs oversample into the megahertz range.

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#166

Earlier quoted context omitted.

Have you ever actually checked the number of actual bits your ADC can use? Most 24 bit converters struggle to get to 18 bits. Nobody uses 32 bit float for recording (to do so is just to capture at least 10 bits of noise, most of that being brownian); its strictly a format for mixing and processing. You don't get any more resolution from 32 bit floating point than you do from 24 bit integer formats, but the result of…

Dude I've been doing sound design on films using these techniques for years. There is zero 'woo' involved, it is ALL practical evidence based use. I've been using 32bit float multitrack field recorder by Sound Devices MixPre10-II professionally for many years now. The recorder has three preamps per mic input, each gain staged to provide optimum signal to the 32bit float AD. Read this to clarify your thinking: https:/…

> I am talking about an industruy you have no knowledge or lived experience with

I'm the original/lead developer of Ardour, a cross-platform DAW, and have been working with digital audio for more than 25 years.

There are no 32 bit ADCs - your SD MixPre's are giving you (at best) 22 bits packaged as a 32 bit float value. The preamps make absolutely zero difference to the AD conversion (though they might sound real nice).

> Surely you understand a recording made at 48kHz has a max freq response of 24kHz and played at half speed that max freq is 12kHz

This is a very naive version of what "played at half speed" might actually mean. If properly and correctly resampled, this is not true.

> And when I load a 192kHz recording to izotope RX I can literallu see the harmonics going up to 96kHz

Well, I'd certainly hope so! But the question is: what are the energy levels associated with the partials above Nyquist? If you recorded at 384kHz with sensitive enough equipment, you'd see partials above 96kHz - but at extremely low energies because ... well, that's just how physics works.

[EDITED to remove AD/DA confusion]

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#167

Earlier quoted context omitted.

Absolutely! All these examples have imperfect audio paths - that is the point.

But the central point is that there's no reason to pick on the digital elements in any particular way. Recorded music in 2026 is a pretty good recreation of the original acoustic pressure waves when it is intended to be , but (a) not perfect, even in the pure analog domain and (b) it is frequently not intended to be.

The central point is that AD conversion can and will introduce artifacts. DA process wil intrduce more artifacts. The "imperfect" is a huge range and AD/DA converters play a role in that. We are not talking about "golden cables" bs here, conversion does introduce measurable artifacts in the audio path. The more tracks you record the more artifacts you have. Can everyone hear them? Definitely no. Can they be heard - yes, I can hear the difference between an old Digidesign interface and Grace Design interface.

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#168
post #41

Earlier quoted context omitted.

A treated room would be the most impactful, DACs the least.

The most impactful for noticing the difference? Again, I would argue it's the trained ear. If you have plenty of mixing experience then all these details add up, and a treated room becomes the most critical - agree with that.

So far, here isn't sufficient evidence that anyone has such reliably golden ears.

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#169
post #124

Earlier quoted context omitted.

This is an extremely hard comparison to do well. I'll give a few examples as to why: Small differences in gain are ABX able much more readily than differences in noise at the 16 vs 24 bit level. So if the signal chain gives even a small difference in gain between the samples that's what you'll track. A reasonable conversion path to 16 bits for mastering will also apply dithering and some kind of brickwall limiting (y…

> Small differences in gain are ABX able much more readily than differences in noise at the 16 vs 24 bit level. This was common knowledge at least as far back as the mid 80s, when every hifi shop and salesguy knew to ensure the bit of gear with the highest profit margin got played an almost imperceptible bit louder than the gear the customer came in to buy during back to back testing.

It's also a reason why double-blind testing is important. If someone doing the setup is expecting one piece of kit to sound better, if it doesn't they'll check the configuration more, and difference in gain can come from many sources. So errors that result in higher gain in favor of the "better" candidate go uncorrected, while ones that favor the worse tends to be fixed.

Point being: it doesn't even require an unscrupulous sales person to get similar results to an unscrupulous sales person! :P

Re: 24-bit/192kHz music downloads and why they make no sense (2012)

#170

Earlier quoted context omitted.

There are precisely zero 32 bit ADCs in existence. There are ADCs that will provide 32 bits per sample but that's entirely different. Current technology limits the bit depth to 18-22 bits and going beyond that you'd be very quickly recording brownian (atomic) noise anyway. The point about 32 bit float is that it is a useful format for mixing, editing and general processing, so it is widely used in digital audio tools…

Rode NT1-A 5th gen microphone claims 32-bit float output, insisting it will not clip peaks so maybe they do sample at 24 bit at a well chosen gain level and then convert to 32 bit float, with the max 24 bit value being above 1.0 float or as GP said, use two separate ADCs at two different gains and combine their output

> Rode NT1-A 5th gen microphone claims 32-bit float output, insisting it will not clip peaks

Of course it does! And that's what it does, of course. But that has absolutely nothing to do with the AD process itself, which is chip-limited to 24 bits and likely physics-limited to somewhat less than that.

You can't beat the physical limit of a DA circuit by doubling them up at different gains.

And .. you don't want to. Going beyond 22 bits gets you into brownian noise pretty quickly, which is completely pointless.

The best you can do (or could do) is get a very, very, very good DA that can really do 22 bits (likely not commercially available because of the expense), and then get the samples from it in whatever format works best for your purpose (24 bit integer, some fixed point value, or 32 bit floating point).

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