I want a high order Papoulis filter whose frequency can be moved in real time. Can I somehow generate Papoulis IIR coefficients and use them inside a bunch of
Background: I’m trying to design an effect, and as part of the algorithm I believe I need to chop off all the information above a certain frequency. This frequency needs to be able to move up and down with automation during the song. I could just use the built-in
IIRCoefficients::makeLowPass(sampleRate, frequency) (that’s just a Butterworth filter, right?), but I love the sound of the 20th order Papoulis filter in the free “ToolChain” VST effect by RS-MET. It seems a little steeper and has a sharper transition at the filter frequency. I’m trying to recreate that in JUCE. I’m no DSP expert, but I’ve read that the best way to get variable higher-order filters is to stack second-order filters. Is that all a Papoulis filter is, a basic second-order IIR filter? I just need to get my hands on the algorithm to calculate those coefficients, right?