[PD] overdriven speaker

Mathieu Bouchard matju at artengine.ca
Sun Nov 14 18:16:39 CET 2010

On Wed, 10 Nov 2010, - wrote:

> By the way it is kind of sad that everyone (including me) always uses 
> tanh, while there are much much more functions out there which could be 
> better suited, produce less high harmonics (aliasing!) or just sound 
> better. A while ago I took a small dive into this topic but only 
> remember some sigmoid functions, but not what their effect was: atan, 
> 1/(1+exp),

1/(1+exp) is the same as tanh, except for the input gain, output gain, and 
output dc.

> x/sqrt(x^2),

That's the same as x/abs(x), which is the limit of tanh as input gain goes 
towards infinity. It's the same as [>~] except when the input is exactly 
zero, and except for the output gain and output dc.

> [sqare-law],

What's this ?

> erf() [I couldn't test because its only in the documentation of expr but 
> not useable] But this should be a topic of its own.

Sorry, but [expr erf($f1)] does work. There are functions in [expr]'s docs 
that don't really exist in expr, but erf is not one of them.

| Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC

More information about the Pd-list mailing list