On Sun, Aug 12, 2012 at 07:38:58PM +0200, "Jérôme M. Berger" wrote:
> Actually, that's one point where PA is right (even though it's > wrong on a lot of other points): doing it like (2) avoids amplifying > the quantification noise if the sound card applies the master gain > in analog (or uses higher bit depths internally before the DACs as > some do). True, if the master is after the DAC, but even then irrelevant. Quantisation noise for a typical 20-bit (or even 16-bit) DA is low enough so it doesn't matter. See previous post. > When cascading amplifiers, it is always better to put the highest > possible gain on the first stages (always leaving enough headroom to > avoid clipping/distortion) so that later stages will not amplify the > noise from the first stages (or so that they will reduce it along > with the signal). The only case when this rule does not hold is when > doing digital processing in floating point (because then the > quantification noise is defined as a proportion of the actual signal > instead of its potential maximum). Correct again. But there's not reason why a software mixer shouldn't use floating point, or a fixed point format (e.g. 32 bit integers) that provides enough room above and below. Please don't tell me that PA is using 16-bit for its internal operations - that would really prove it's complete crap. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)
