HPF 2nd order Butterworth highpass filter

HPF.ar(in, freq, mul, add)

A second order high pass filter. 

in - input signal to be processed

freq - cutoff frequency.

{ HPF.ar(Saw.ar(200,0.1), FSinOsc.kr(XLine.kr(0.7,300,20),0,3600,4000), 5) }.play;

(

{ var ctl = HPF.kr(LFSaw.kr(5), SinOsc.kr(XLine.kr(0.07,30,20), 0, 35, 40)) ;

SinOsc.ar(ctl * 200 + 500);

}.play;

)

(

{ var ctl = HPF.kr(LFSaw.kr(5,0.1), MouseX.kr(2, 200, 1));

SinOsc.ar(ctl * 200 + 400) * 0.1;

}.play;

)