* Antoine Rousseau <anto...@metalu.net> [2024-04-11 13:40]: > That doesn't seem incorrect to me; after all, a lowpass filter at 0Hz > implies that its output is constant (any change would involve frequencies > > 0Hz).
Thanks Antoine, Why does a lowpass filter, that has a cutoff frequency of 0Hz imply that it's output is constant? I will describe the problem again hoping that I will understand it better myseld: I have an oscillating input signal that has some DC offset (unipolar sawtooth from phasor~). I fade this signal's amplitude to -inf dB using [line~]. I also fade down the filter cutoff (defined as the -3dB point of the filter curve) from 400Hz to 0Hz. The filter will then continue to produce an non-decaying output. If I fade down the filter cutoff down to only 1Hz, it's output will decay (somehow counterintuitively to me). This is the part I don't get. I understand that vcf~ is a resonant filter, and it can have a gain greater 1 around the cutoff frequency, especially for high Q values. The above behavior can also be observed for Q=1. Thanks for all hints! Peter _______________________________________________ Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
