RLPF

RLPF.ar(in, freq, rq, mul, add)

A resonant low pass filter. 

in - input signal to be processed

freq - cutoff frequency.

rq - the reciprocal of Q.  bandwidth / cutoffFreq. 

{ RLPF.ar(Saw.ar(200,0.1), FSinOsc.kr(XLine.kr(0.7,300,20),3600,4000), 0.2) }.play;

(

{ var ctl = RLPF.ar(Saw.ar(5,0.1), 25, 0.03);

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

}.play;

)

(

{ var ctl = RLPF.ar(Saw.ar(5,0.1), MouseX.kr(2, 200, 1), MouseY.kr(0.01, 1, 1));

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

}.play;

)