Re: [LAD] FULL audio-signal path

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.

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Received on Mon Jul 23 20:15:02 2007