These two filters are based on the asdev filter code, which is available on buzztrack. I added inertia and
remapped the cutoff values so they are logarithmic (also limited the resonance, and made some changes to avoid
pops in the low end). The original code is very good (if not a drop slow), and sounds very analog (it looks to me
like a simulation of a moog filter), but it was unusable because it had no inertia, and also popped a lot. This
fixes those problems and even with inertia it is still about the same speed (due to a few tricks of mine). 

Enjoy

-WhiteNoise
dwallin@planetquake.com
www.mp3.com/lowpass