~A7.5,22.5;L-10,1000;	FA45a~
L-650,750;FABLOCK~
L-650,720;FADIAGRAM~
L-533,600;→l-333,600;L-267,600;→l-100,600;
L100,600;→l500,600;
L300,600;l300,750;→l40,750;L-40,750;l-300,750;→l-300,633;
L0,600;B100,40;	L-50,590;F9DELAY m~
L-300,600;C33;	L-308,590;FA+~
L0,750;B40;	L-8,740;F9g~

L200,-50;
X0.9; Y0.9; *COMB.PLT; X1.0; Y1.0;
L-650,250;FAIMPULSE~
L-650,220;FARESPONSE~
L-300,310;
F8A~L-300,290;
F8M~L-300,270;
F8P~L-300,250;
F8L~L-300,230;
F8I~L-300,210;
F8T~L-300,190;
F8U~L-300,170;
F8D~L-300,150;
F8E~L150,-50;F8TIME~

L200,-600
X0.9; Y0.9; *FCOMB.PLT; X1.0; Y1.0;
L-650,-300;FAFREQUENCY~
L-650,-330;FARESPONSE~
L-300,-240;
F8A~L-300,-260;
F8M~L-300,-280;
F8P~L-300,-300;
F8L~L-300,-320;
F8I~L-300,-340;
F8T~L-300,-360;
F8U~L-300,-380;
F8D~L-300,-400;
F8E~L50,-600;F8FREQUENCY IN KHZ~

M1NGB25;
L-550,-860;
FAFigure 14.~
L-350,-860;F1Comb filter with gain, G, and delay, m.
~~L-10,1000;	FA46a~
L-650,750;FABLOCK~
L-650,720;FADIAGRAM~
L-533,600;→l-333,600;L-267,600;→l-100,600;
L100,600;→l267,600;L333,600;→l533,600;
L-433,600;l-433,450;→l-40,450;L40,450;l300,450;→l300,567;
L433,600;l433,750;→l40,750;L-40,750;l-300,750;→l-300,633;
L0,600;B100,40;	L-50,590;F9DELAY m~
L-300,600;C33;	L-308,590;FA+~
L300,600;C33; 	L292,590;FA+~
L0,750;B40;	L-8,740;F9g~
L0,450;B40;	L-15,440;F9-g~I1550,1060; 
X0.9; Y1.7; *FIRST.PLT; X1.0; Y1.0;
L-650,0;FAIMPULSE~
L-650,-30;FARESPONSE~
L-300,60;
F8A~L-300,40;
F8M~L-300,20;
F8P~L-300,0;
F8L~L-300,-20;
F8I~L-300,-40;
F8T~L-300,-60;
F8U~L-300,-80;
F8D~L-300,-100;
F8E~L150,-100;F8TIME~

L-550,-860;
FAFigure 15.~L-350,-860;
F1The first-order all-pass unit  reverberator. By adding -G times~L-450,-890;
F1the input into the output of the delay, we change a comb filter~L-450,-920;
F1into an  all-pass.  Since  the  frequency  response is unity, it~L-450,-950;
F1is not shown here.
~~L-10,1000;	FA47a.~
L-650,400;FABLOCK~
L-650,370;FADIAGRAM~
L-400,550;B100,40;	L-450,540;F9DELAY m~
L-400,250;B100,40;	L-450,240;F9DELAY m~
L400,250;B100,40;	L350,240;F9DELAY m~
L-175,400;C33;	L-183,405;FA+~	L-183,375;FA-~
L575,400;C33;	L567,390;FA+~
L175,250;C33;	L150,237;FA-~	L168,263;FA+~
L400,700;B40;	L390,690;F9G1~
L0,400;B40;	L-10,390;F9G2~
L0,250;B40;	L-10,240;F9G1~
L-750,700,→l360,700;L440,700;l575,700;→l575,433;
L-600,700;l-600,550;→l-500,550;
L-300,550;l175,550;→l175,283;
L-175,550;→l-175,433;
L-142,400;→l-40,400;L40,400;→l542,400;
L-300,250;→l-40,250;L-175,250;→l-175,367;
L40,250;→l142,250;L208,250;→l300,250;
L500,250;l575,250;→l575,367;
L608,400;→l750,400;
L675,400;l675,65;l-600,65;l-600,250;→l-500,250;

I1600,1050; 
X0.9; Y1.1; *NUAP.PIC; X1.0; Y1.0;
L-650,-250;FAIMPULSE~
L-650,-280;FARESPONSE~
L-300,-210;
F8A~L-300,-230;
F8M~L-300,-250;
F8P~L-300,-270;
F8L~L-300,-290;
F8I~L-300,-310;
F8T~L-300,-330;
F8U~L-300,-350;
F8D~L-300,-370;
F8E~L150,-650;F8TIME~

L-550,-860;FAFigure 16.~L-350,-860;
F1The second-order (oscillatory) all-pass unit reverberator