Re: LOOPING a DRY CLEANING SHOP

[Rainer Straschill <moinsound@googlemail.com>]

Am 02.10.2011 09:13, schrieb andy butler:
> Rainer Straschill wrote:
>
> > In fact, you can turn any sound into any sound using only linear 
> > processing 
>
>
> now, is that right?
>
> http://www.dspguide.com/ch5/4.htm
>
> ...of course, that's only a nitpick about the term "linear"
Your nitpicking is always welcome, Andy...but here's what I learned in 
school.

A system is linear, if for a function describing it f and input 
functions x, y (which can be vectors or whatever), and a scalar a, the 
following holds.

f(a*(x+y))=a*(f(x)+f(y)).

This is true for the things we know (with recent accuracy) for home 
stereo amplifiers, delays, EQs. It is not true for distortion pedals, 
guitar amplifiers etc.

Now there is proof (and I don't want to repeat that here, but it goes 
somewhat via Feldtkeller and Richardson) that every linear system can be 
seen as a combination of delays, adders and amplifiers.

Soooo...where does that contradict your link? None of these building 
blocks are in that article's "nonlinear" category.

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