[PD] biquad~ vs. svf~

[guenter geiger]

On Fri, 27 Feb 2004, Tim Blechmann wrote:
> hi all,
>
> i'm currently using biquad filters (i'm getting the settings from
> iemlib's lowpass, highpass (...) externals).
> i consider to change my patch to use svf~ from the cyclone library.
>
> does anyone know, which algorithm is more expensive in terms of cpu
> time? and are there any mayor differences in the characteristics of
> these two filter types?

I think they are completely different. Biquad~ at least is not really
good if you want to control in the signal domain. The lowpass etc
externals implement the filters from here:

 http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt
 written by Robert Bristow-Johnson

Then the last time I saw them they were written by me, and not part of
the iemlib, but how knows, ... in reality the hard work was done by
Robert Bristow-Johnson.

Guenter