#63 Add 'classic' filters with resonance control

[Chris Arndt]

A feature request:

add some filters, which emulate classic synthesizer filters and have a resonance control, e.g. the Moog Ladder filter. This would make it possible to create many typical sci-fi sound effects based on noise and modulation of a resonant filter.

This moog 24db low-pass filter emulation is easy to implement and sounds good:

http://www.musicdsp.org/archive.php?classid=3#24

Alternatively, add a framework to define your own filter functions within the Nsound API in Python or as a C extension.

[Nick]

[r910] doesn't work yet ...

[Nick]

[r911]