A single pole allpass filter has the following general phase response: Graph of Allpass phase rotation.
The equation of an allpass is given here: Phase equation of an allpass.
Allpass filters in general are discussed here.
I am wondering how I can graph the phase response of an allpass filter in desmos.com like given by this graph given a specified fc (cutoff frequency).
Secondly, I am wondering how I can graph the phase response of two allpass filters in series with different specified cutoff frequencies for each.
Any help? What do I need to put in Desmos to get these things to graph?
Thanks.