Smoothing IIR Filter Response

Hi everyone,

I am experiencing a problem where if I have the gain turned up on an IIR peak filter, and reset the frequency to 20 Hz, from 10kHz - 20kHz, a loud pop that occurs. I’m guessing that the pop is a product of some built-in smoothing, that is trying to happen too quickly over one buffer length. I don’t know how to solve this issue. I’m also not sure what code I would share to address the problem. Do you all have some ideas of where to start?

Thank you,

Last time I checked, there was no coefficient smoothing in the dsp::IIR filters, which might be your problem. Aprupt changes in the coefficients are known to cause discontinuities in the filtered signal.

Gotcha, no worries. Thank you!

dsp::StateVariableFilter and dsp::StateVariableTPTFilter have automatic cutoff frequency change smoothing however :wink:

1 Like