[ladzoppelin]

"Professional audio will typicall utilize 24-bit. Everything higher than that is usually bogus. Bogus where only audiophiles will hear a difference." Does he mean internal DAW bit rates like 64/32bit float are bogus, I am probably reading it wrong ?

[hatthew]

If you listen to an audio file at 24 bit vs 64 bits (bit depth, not bitrate), you won't notice a difference. However, if you're manipulating audio in a DAW or similar, it's possible for noise to end up amplified in the final output, so a higher bit depth could make a difference.

Think of it this way: every time you add a filter or any type of audio manipulation in your DAW, you're discarding some information and replacing it with noise (how much depends on what manipulation you're doing, but it's almost always >0). If you start at 24 bits and then don't manipulate anything, it's all good. But if you start at 24 bits and then lose 10 bits of the true signal, you're down to just 12 bits of information. But if you start at 64 bits, you can lose 40 bits before you start to notice anything (or really it depends quite a lot on many different factors, but in general there's a threshold where noise goes from "not noticeable" to "noticeable" and it's probably usually between 8 bits and 32 bits).

Don't quote me on the details (I am not an audio engineer or anything even slightly related), but that's the general gist of it.

[swatcoder]

I read them as talking about listening, as represented in mentioning audiophiles.

The extra depth/range available in DAW's are useful for effects processing, mixing, and mastering and are a little colored by trying to squeeze max-performance DSP on a general-purpose/commodity CPU. I just don't take them as talking about that here though.

[tialaramex]

And the bits are basically free. If we had very cheap 24-bit floats and nothing bigger, maybe we'd use those, but we've got cheap 32-bit floats, so those are fine.

The most important property of floating point is "infinite headroom". In integer space, sixteen times quieter means 4 fewer bits of audio, get the levels wrong badly enough and people can hear your mistake even if you fix it later - but in float space it barely makes any difference, so long as the levels are correct in the final consumed audio nobody cares.

[PaulDavisThe1st]

We would NOT use 24 bit floats since that would make them less than ideal at matching the hypothetical (and almost certainly never reach) 24 bit resolution of integer DAC/ADC hardware.

The reason why 32 bit floats work great is that they can handle a 24 bit integer without any loss, and then if for some reason the values get kicked up above the maximum you can represent there, you get subtle noise rather than heavy distortion.

[tialaramex]

I don't think I agree. As you say, those extra few bits in your integer PCM are probably just noise, worse they might be correlated noise. They're not worthless, but I can't agree that they're automatically better than the infinite headroom option.

We don't have a world with 24-bit float DAWS, in our world stuff tends to offer 32-bit float, and so that's a no brainer, but just as I'm sure the 14-bit CD would have been perceived much the same as our world's 16-bit CD (bad engineers would do a bad job with it, good engineers would learn to use it well, some people would hate it for no reason), I think 24-bit float in the studio would have similar fans to 32-bit float.

[creeble]

“16 times quieter” is not 4 bits.

“Half volume” is subjective, and for music is typically between 6 and 10dB (most US audio engineering classes use 10dB).

[Joeboy]

I think he's kind of wrong. As you say, anything going through any kind of professional audio editing software is probably 32/64 bit float. AFAIK all audio plugin standards work on 32/64 bit floats.

Although I imagine at least historically that's more because 32 bit floats are a native data type.

[Zamiel_Snawley]

I don’t deal with audio, but I do use high frequency DACs/ADCs.

I have never found a DAC that actually has useful/detectable output differences above 16-18 bits. I’m not talking about audible, I mean with oscilloscopes. Many DACs take 32 bit inputs, but those extra bits aren’t useful in the real world.

The integral and differential non linearity of DACs in the real world make those extra bits misleading.