What's the point of higher sampling rates in audio?, Such as 96 and 192kHz. Options

[stranhoROX]

Could someone explain to me why there are some recordings with sample rates as high as 192kHz? If most of us hear up to 20kHz, wouldn't 44.1kHz or even 48kHz be enough? Or is there other practical aspects besides boosting maximum frequency in higher sampling rates I am not aware of?

[2Bdecided]

@benski,

...but if you're simply relying on the high sample rate to keep processing aliases out of the audible band, you need to go into the MHz for some operations. Or do them in a smarter way. I agree that keeping the base Nyquist limit a little higher when you're resampling through each of many different DSPs can help in an objective and measurable sense: it can mitigate some of the effects of careless processing and/or resampling in each DSP module. This can be audible is the processing is bad enough - e.g. really trashy resampling. But is the improvement enough to turn trash into perfection? No.

C.R.Helmrich's response is right IMO - people do it because they can, and they believe it sounds better. Despite an almost total lack of any corroborating evidence. Plus a few people will pay more for a recording at a higher sample rate, for the same reason.

EDIT Examples:
http://www.soundkeeperrecordings.com/purchase.htm
http://www.paulmccartney.com/bandontherun/gbp.html

I guess the question becomes: why wouldn't you do it? If it costs nothing, and sells one more copy, or lets you charge some people more, or gets you bragging rights in some circles, then it's "worth it" - even if the technical benefit is zero.

Cheers,
David.

This post has been edited by 2Bdecided: Oct 17 2011, 10:11

[benski]

@benski,

...but if you're simply relying on the high sample rate to keep processing aliases out of the audible band, you need to go into the MHz for some operations. Or do them in a smarter way. I agree that keeping the base Nyquist limit a little higher when you're resampling through each of many different DSPs can help in an objective and measurable sense: it can mitigate some of the effects of careless processing and/or resampling in each DSP module. This can be audible is the processing is bad enough - e.g. really trashy resampling. But is the improvement enough to turn trash into perfection? No.
David.

Sure, but for polynomial equations (or polynomial approximations of transcendental functions), the aliasing is predictable. Because multiplying two signals M and N will produce a sideband at M+N, each polynomial order will require an equivalent increase in sampling frequency. Certainly there are other aliasing-reducing techniques such as using an all-pass for fractional delays and minBLEP for waveform generation, but for resonant IIR filters, especially, the higher sample rate can really make a difference (and admittedly most plugins probably upsample/downsample internally)

Note that I'm not at all trying to imply that high sample rate in final, delivered, consumer audio is justified. I'm just pointing out that doing the mixing and production at high sample rate is worthwhile. And if you already have a 192kHz master, why not try to sell it for a few bucks more?

[dhromed]

And if you already have a 192kHz master, why not try to sell it for a few bucks more?

Great, so why not sell the 44.1 version for a few bucks less?