arnyk wrote: > I sense a misunderstanding of quantization (the correct term - not > quantification) noise. Quantization noise is not added in, rather it is > an inherent component of the digitized signal. Strictly speaking calling > it a noise is a questionable use of the word noise, as noise is usually > a random signal, while quantization noise is not random but rather 100% > periodic and predictable. Quantization error or quantization distortion > would be more accurate terms. At the most quantization error is pseudo > random since it is actually 100% periodic and predictable. > > In the lexicon of electronics, it would probably be more logical to call > it a distortion. Calling it a noise is an artifact of the days when it > was not fully understood, and thought to be a noise. The convention > continues to be used. Everybody recognizes the word as an identifier > even though it is not a 100% accurate use of the terminology. > > The peak value of quantization error is 1/2 of the LSB. Its average or > RMS values are proportionately less because RMS and average measurements > tend to average out the peaks. > > If the signal is dithered, the total noise in the signal need not > increase, because the true function of dither is to overcome the > periodic nature of quantization error, and replace it with something > that is perceived by the human ear to be random. My choice of words was a bit careless but the point remains. Whether quantisation error is termed noise or distortion is neither here nor there. The issue is what bit depth may capture -without degradation- a recording with a given noise floor. Quantisation must add some uncertainty. The better point which you might have made was that it may not be necessary to dither given the analog noise which may make the recording self dithering. Now whether that means that the total noise power remains the same in the quanitsed and pre-quanatised signal remains the question. I think it is increased and that the self dithering merely makes the quantisation error noise rather than distortion. S we add noise totalling -96dB (?) across the full spectrum (slightyl better than if we had had to dither)
So the question remains- is that additional noise perceptible. I would guess not, provided that it is 10dB or so below the existing noise floor. ------------------------------------------------------------------------ adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=105717 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
