Quote:
Originally Posted by Dan Lavry  Much of the limitations in dynamic range of both “analog only” and converter devices is due to noise generated by components (resistors, semiconductors and even small value caps). Take resistor noise, and you find that it increases with bandwidth (though not linearly, but as a square root of the bandwidth). If one provides more bandwidth, you end up with MORE NOISE. You do not deal with a fixed amount of noise spread over more bandwidth. This notion is plain wrong. The statement that noise goes up by a square of the bandwidth is correct, so double the bandwidth means 3dB more noise (not 6dB), but that is still more noise, not less noise… |
Thanks for the reply Dan, that's very interesting. Makes sense that if one assumes there to be self noise in a system, sampling bandwidth has an influence on the amount of noise recorded. I have no doubt that such real life limitations are very much of importance.
However, I'm also interested in the theoretical,
generic claim made in the original post: That in any (non-dithered) PCM recording system, sampling rate supposedly has an influence on SNR. First, I don't understand how that is possible because a generic undithered PCM system has no noise floor. All perceived "noise" will be quantization noise, i.e. harmonic distortion, so we're not talking about SNR but amount of distortion. If that's what the original post is referring to, then I'm asking how the relative amount of (perceived) harmonic distortion can possibly change with sampling rate (assuming both system's sampling rates are sufficient to cover the audible range).
If the original post is referring to a dithered system, then there can of course be a connection between sampling rate and
perceived SNR because of the dither spreading over an increased bandwidth (or intentionally being shaped) into the inaudible range. But the OP is specifically saying that this is not what he's talking about. So I'm wondering what exciting new development in PCM I missed in the last decade.