perm filename REVINF[IRC,LCS] blob
sn#053243 filedate 1977-03-30 generic text, type T, neo UTF8
00200 ARRAY D1(801),D2(901),D3(1011),D4(1123),D5(123),D6(43),D7(13);
00300 VARIABLE /R;
00500 REVINIT←1;R←0;
00600 COMPILE;
00700 INSTRUMENT REV;
00800 REV1(R,801,.827,D1);
00900 REV1(R,901,.805,D2);
01000 REV1(R,1011,.783,D3);
01100 REV1(R,1123,.764,D4);
01200 REV2(U1+U2+U3+U4,123,.7,D5);
01300 REV2(U5,43,.7,D6);
01400 REV2(U6,13,.7,D7);
01500 R←0;OUTA←OUTA+U7;OUTB←OUTB+U7;
01700 END;
01800 FINISH;
01900
02000 <THE TOP LINE DECLARES THE ARRAYS TO BE USED. THE RUN-TIME
02100 <VARIABLE R PICKS UP DATA FROM THE REGULAR INSTRUMENTS TO PASS
02200 <ON TO THE REV INSTRUMENT. (THE SLASH IN FRONT OF THE
02300 <R MAKES IT A RUN-TIME VARIABLE. I.E. ITS VALUE MAY BE CHANGED
02400 <FROM SAMPLE TO SAMPLE - AS OPPOSED TO ORDINARY VARIABLES [NO
02500 <SLASH WHEN THEY ARE FIRST DECLARED] WHICH ARE FIXED EACH TIME THE
02600 <PARAMETERS FOR AN INSTRUMENT ARE READ IN. HENCE THE VALUE OF R
02700 <WILL CHANGE FOR EACH SAMPLE.) EACH TIME INSTRUMENT REV COMPUTES
02800 <A SAMPLE R IS SET BACK TO 0 (LINE 1300) SO THAT DATA FROM ONE
02900 <SAMPLE WILL NOT MIX WITH THAT FROM THE NEXT. THE REV1 AND REV2
03000 <UNIT GENERATORS ARE ESSENTIALLY FEEDBACK LOOPS WITH DELAY TIMES
03100 <(IN SAMPLES) EQUAL TO THE FIRST NUMBER APPEARING IN THE PARENTHESES,
03200 <WITH THE SECOND NUMBER (LESS THAN 1) BEING THE MULTIPLIER (OR
03300 <GAIN) USED EACH TIME A SAMPLE MAKES THE LOOP.
03400
03500 < THE USUAL WAY TO USE REVERBERATION IS TO TAP THE OUTPUT OF
03600 <EACH INSTRUMENT, PUTTING A PERCENTAGE OF THE SIGNAL INTO R (USUALLY
03700 <10 TO 20%). THE RELATIONSHIP BETWEEN THE PERCENTAGE OF DIRECT
03800 <SIGNAL TO THE PERCENTAGE OF REVERBERATED SIGNAL SEEMS TO BE THE
03900 <THE MOST IMPORTANT ELEMENT IN GIVING THE ILLUSION OF VARYING
04000 <DISTANCES.
04100
04200 < IN THE FOLLOWING EXAMPLE IT WILL BE ASSUMED THAT 5 UNIT
04300 <GENERATORS INVOLVING 8 PARAMETERS ARE USED IN THE INSTRUMENT
04400 <PROPER. THEN THE LAST LINES WOULD BE:
04500
04600 < R←R+U5*P8;
04700 < OUTA←OUTA+U5*(1-P8);
04800 < END;
04900
05000 < THUS P8 WILL HAVE THE PERCENTAGE OF THE SIGNAL TO BE
05100 <REVERBERATED. IF STEREO IS USED THE FIRST LINE REQUIRES NO
05200 <CHANGES BUT THE REMAINING SIGNAL, AS INDICATED BY "*(1-P8)",
05300 <WILL BE SPLIT BETWEEN THE CHANNELS IN WHATEVER MANNER MAY
05400 <BE DESIRED.
05500
05600 < IN GENERAL THE REV INSTRUMENT SHOULD BE TURNED ON ONLY ONCE,
05700 <"PLAYING" ONE LONG "NOTE" FOR THE DURATION OF A PIECE.
05800 <IN THE FOLLOWING EXAMPLE THE ASSUMPTION IS THAT THE TOTAL
05900 <DURATION OF THE REGULAR NOTES IS 42". REV PLAYS 2" LONGER TO
06000 <ALLOW THE REVERBATION TO DIE AWAY.
06100
06200 < REVINIT←1;R←0;
06300 < PLAY;REV 0 42;
06400 < --- [ALL THE NOTES FOLLOW] --
06500 < FINISH;
06600
06700 < IF A LONGER WORK (SAY 2 1/2') IS TO BE DONE IN SECTIONS -- FOR
06800 <EVENTUALLY EITHER ONE LONG PLAY FROM THE COMPUTER OR FOR TAPE
06900 <SPLICING OF THE SEPARATE SECTIONS -- DO AS FOLLOWS:
07000
07100 < REVINIT←1;R←0;
07200 < PLAY;REV 0 37.3;REVINIT←0;
07300 < --- [THE NOTES FOR EXACTLY 37.3" FOLLOW] --
07400 < FINISH;
07500
07600 < -- THEN, USING THE SAME CORE IMAGE (SO THE LAST STATE OF THE
07700 <REVERBERATOR WILL BE PRESERVED):
07800
07900 < PLAY;REV 0 78;
08000 < --- [NOTES FOR EXACTLY 78"] --
08100 < FINISH;
08200
08300 < -- THEN THE FINAL SECTION*
08400
08500 < PLAY;REV 0 37;
08600 < --- [NOTES FOR THE LAST 34.7"] --
08700 < FINISH;
08800
08900 < WHEN THESE THREE PARTS ARE PIECED TOGETHER THERE WILL BE NO
09000 <GAPS IN THE REVERBERATION, WHICH WILL EXTEND 2.3" BEYOND THE FINAL
09100 <NOTE.
09200
09300 < I AM NOT TOO SURE ABOUT THE FUNCTION OF REVINIT. I BELIEVE IT
09400 <MUST BE SET BACK TO ZERO AFTER! THE FIRST PLAYING OF REV IF YOU
09500 <WISH TO HAVE THE REVERBERATION CARRY OVER FROM ONE PLAY;...FINISH;
09600 <INTO THE NEXT.