[LAD] FULL audio-signal path

[Jens M Andreasen]

On Mon, 2007-07-23 at 14:16 +0200, Fons Adriaensen wrote:
> On Sun, Jul 22, 2007 at 01:29:19PM -0400, Paul Davis wrote:
> 
> > 2) there are some good theoretical arguments for needing more than 32bit
> > floating point resolution for a mixer
> 
> I did a quick experiment. 
> 
> N floating point signals, all of them Gaussian distributed, summed
> both as single and double precision. If the difference between the
> two sums is considered 'noise', the signal/noise ratios R in dB are:
> 
>     N      R
> ----------------
>    16   -142.9
>    32   -140.0
>    64   -136.7
>   128   -133.8
>   256   -130.7
>   512   -128.0
>  1024   -124.7
>  2048   -121.9
>  4096   -118.8

Even for this (most simplistic) summing example, an error or noise floor
at -118.8 dB would still be like comparing the sound of a deafening
jet-engine close up, to that of some rustling leaves in the background
(which may or may not be missing in your soundscape  ...) Hardly
noticeable.

I also wonder ... Suppose channels 1 - 4095 were an orchestra of
assorted, close miked vacuum cleaners and hair dryers, and channel 4096
was a sole bagpiper. Would you then be able to figure out wether he is
playing Auld Lang Syne or not? 

:)

I would suspect the bagpipe to be lost. With that [4096] amount of
channels, we are approaching something compareable to that of a football
choir at a stadium, were one individual has no impact whatsoever on the
resulting sound.