LPF 2nd order Butterworth lowpass filter

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

A second order low pass filter. 

in - input signal to be processed

freq - cutoff frequency.

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

// kr:

(

{ var ctl = LPF.kr(LFPulse.kr(8), SinOsc.kr(XLine.kr(1, 30, 5)) + 2);

SinOsc.ar(ctl * 200 + 400) 

}.play;

)

(

{ var ctl = LPF.kr(LFPulse.kr(8), MouseX.kr(2, 50, 1));

SinOsc.ar(ctl * 200 + 400) 

}.play;

)