#N canvas 185 22 655 349 12;
#X obj 27 14 biquad~;
#X msg 448 11 \; pd dsp 1;
#X msg 448 55 \; pd dsp 0;
#X obj 84 248 env~;
#X floatatom 84 275;
#X floatatom 15 110;
#X obj 15 246 env~;
#X floatatom 15 274;
#X text 13 297 Compare the value of the straight signal on the left with the value of the filtered signal on the right.;
#X obj 84 215 biquad~ 1.41407 -0.9998 1 -1.41421 1;
#X msg 101 121 1.41407 -0.9998 1 -1.41421 1;
#X text 76 31 calculates the following difference equation:;
#X text 77 44 y(n) = ff1 * w(n) + ff2 * w(n-1) + ff3 * w(n-2);
#X text 76 58 w(n) = x(n) + fb1 * w(n-1) + fb2 * w(n-2);
#X text 18 76 Syntax: biquad~ fb1 fb2 ff1 ff2 ff3;
#X text 341 213 this biquad~ is a notch filter for fn = Pi/4;
#X text 390 226 (= SR/8 = 5512.5 Hz @44.1k);
#X text 91 14 2-pole-2-zero-filter;
#X text 113 99 list sets filter parameters;
#X msg 119 161 set 0 0;
#X msg 120 186 clear;
#X obj 15 170 osc~ 5512.5;
#X text 422 337 updated for Pd version-0.30;
#X text 189 163 set internal state;
#X text 187 185 ... or just clear it;
#X connect 3 0 4 0;
#X connect 5 0 21 0;
#X connect 6 0 7 0;
#X connect 9 0 3 0;
#X connect 10 0 9 0;
#X connect 19 0 9 0;
#X connect 20 0 9 0;
#X connect 21 0 6 0;
#X connect 21 0 9 0;