Why does this click and pop when the filter freq changes? I've tried sticking a [line] in there, but it doesn't seem to help.

Its just a simple [adc~] to [dac~] with a low pass biquad in the middle

http://www.pdpatchrepo.info/hurleur/biquadtest.pd

It's because [biquad~] has a non-signal inlet and doesn't do any interpolation internally when the values change. So they basically just quickly jump at block boundaries.

If you look at my mmb library, you'll find an abstraction called [biquadm.mmb~] that smoothly interpolates the values when updated, so you won't hear the clicks.

cool deal!

thanks