High Playback Sampling Frequencies, Why are they becoming popular? Options

[icstm]

OK, at the risk of sounding completely stupid?

Why do people listen to music with high sampling frequencies?
What is 88k+ providing them?
I understand why you might record at a high sampling rate, but why keep that for playback?

Looking through the FAQ, there are threads from 2003 that point out that the sampling frequency and bit-dept work in tandem. So the quantisation error of 16bit at 44.1k has the opportunity to be corrected sooner at a higher sampling rate, so in some ways is like a dithering pattern.

However given noise introduced in the analogue systems required to listen to music, a SNR within a 16bit signal of ~96dB seems pretty good.

So assuming that speakers struggle to produce the sounds that a 192k sampling frequency allow (eg 96kHz) and assuming that 16bits were sufficient when compared to the analogue equipment in the system, what have I missed in these high sampling playback formats?

[icstm]

Have we conveniently forgotten that CD players commonly employed over sampling in order to aid in reconstruction?

In the DAC? That is fine, they are not trying to create information that is not there they are doing signal processing. I am no expert, but I think I am comfortable with a DAC using oversampling and for the rest of the consensus of the argument posted through the thread to remain.

Prior to 'storing for playback at 44.1kHz' one has to downsample, which implies and includes steep anti-alias filtering at 22.05kHz. Sort of back to square 1, not?

Why would I have to do that. The signal has already been sampled. I already have the information in a desired format. The issue is that I have "too much" information. So I need to drop some of it. An anti-alias filter would be used if I was ambiguous about the information I have, but (assuming I used one before whilst working with the higher sampling rates) I am not. I know what frequencies I have.

In fact, before I sample to 44.1, I could process my signal at the higher sampling rate to not include frequencies above 22k. Remember that this is not an anologue information, where I might worry about a low-pass filter, this is in the digital domain.

Does that make sense?

[saratoga]

Have we conveniently forgotten that CD players commonly employed over sampling in order to aid in reconstruction?

In the DAC?

Yes. Modern DACs are oversampled. It gives you better bit depth and less risk of aliasing essentially for free.

In fact, before I sample to 44.1, I could process my signal at the higher sampling rate to not include frequencies above 22k. Remember that this is not an anologue information, where I might worry about a low-pass filter, this is in the digital domain.

... which is what a modern oversampling ADC does. I suspect you think that a 44.1khz ADC/DAC actually runs at 44.1khz. This is not the case and has not been for perhaps 2 decades with the advent of practical CMOS transistors. Common 384x oversampling implies frequencies in the MHz where digitally applying the anti-alias filter is simple.

So yes, what you're saying is a sound idea. So sound its already integrated into every ADC/DAC you've ever used

Edit: wrote DAC when I meant ADC

This post has been edited by db1989: Feb 21 2012, 13:32

Reason for edit: second quote was mistakenly attributed to WernerO (see Recycled topic 93594)