[LAU] [ANN] Songs 0.4pre1 and some help on equalizer

Hi everyone, here is a pre-release of songs 0.4: http://sed.free.fr/songs/songs-0.4pre1.tar.gz (pre1 because I will use it to record some stuff and do a release after that, to catch some bugs) There is a reverb (order 15 CFDN, coming from sverb, but some parameters may not be that good, so the quality is far from perfect for an order 15 CFDN I guess). There is an equalizer (kind of "programmable eq," ie. you write some code and the equalizer's parameters are generated). I am not satisfied with the equalizer (it's a FIR designed with basic window method). So I need some help. What kind of equalizer do you use (like "10 band graphic eq" or "parametric eq") (and with which software, possibly free so I can read the source)? If you are good at DSP, I would like to generate an IIR filter out of my input (an arbitrary frequency response coming from some user's instructions) instead of a FIR. Any technique/pointer to some documentation/code? Thanks, Cedric.