Hi Damian,

Damian Stewart wrote:

by default lp~ and hp~ have very gentle cutoff curves. what should i use to get a nice sharp(er) cutoff point? i'd love to be able to mimic the ableton live eq4 object if i could, it's the biggest thing i miss in pd.

I used the [highpass], [bandpass] and [lowpass] objects from the GGEE library to generate the filter coefficients for a series of raw [biquad~] objects in order to make a "DJ filter" a while back, and was fairly pleased with the results:

http://lists.puredata.info/pipermail/pd-list/2005-10/031738.html

You can get a sharper cutoff by stacking these filters, the normal [lp~], [bp~], [hp~] or any other sets of filters together in series. Thus, a "3 pole filter" might be something like this (somebody stop me if I oversimplify, I'm no mathematician!):

[lp~ 60] | [lp~ 60] | [lp~ 60]

etc etc etc.

best, d.