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<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ; Audio out Audio in -odac -iadc ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o biquad-2.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Required settings for WebAudio: sr = 48000 ksmps = 128 nchnls = 2 nchnls_i = 1 ; sr = 44100 ; kr = 4410 ; ksmps = 10 ; nchnls = 2 /* modal synthesis using biquad filters as oscillators Example by Scott Lindroth 2007 */ instr 1 ipi = 3.1415926 idenom = sr*0.5 ipulseSpd = p4 icps = p5 ipan = p6 iamp = p7 iModes = p8 apulse mpulse iamp, 0 icps = cpspch( icps ) ; filter gain iamp1 = 600 iamp2 = 1000 iamp3 = 1000 iamp4 = 1000 iamp5 = 1000 iamp6 = 1000 ; resonance irpole1 = 0.99999 irpole2 = irpole1 irpole3 = irpole1 irpole4 = irpole1 irpole5 = irpole1 irpole6 = irpole1 ; modal frequencies if (iModes == 1) goto modes1 if (iModes == 2) goto modes2 modes1: if1 = icps * 1 ;pot lid if2 = icps * 6.27 if3 = icps * 3.2 if4 = icps * 9.92 if5 = icps * 14.15 if6 = icps * 6.23 goto nextPart modes2: if1 = icps * 1 ;uniform wood bar if2 = icps * 2.572 if3 = icps * 4.644 if4 = icps * 6.984 if5 = icps * 9.723 if6 = icps * 12.0 goto nextPart nextPart: ; convert frequency to radian frequency itheta1 = (if1/idenom) * ipi itheta2 = (if2/idenom) * ipi itheta3 = (if3/idenom) * ipi itheta4 = (if4/idenom) * ipi itheta5 = (if5/idenom) * ipi itheta6 = (if6/idenom) * ipi ; calculate coefficients ib11 = -2 * irpole1 * cos(itheta1) ib21 = irpole1 * irpole1 ib12 = -2 * irpole2 * cos(itheta2) ib22 = irpole2 * irpole2 ib13 = -2 * irpole3 * cos(itheta3) ib23 = irpole3 * irpole3 ib14 = -2 * irpole4 * cos(itheta4) ib24 = irpole4 * irpole4 ib15 = -2 * irpole5 * cos(itheta5) ib25 = irpole5 * irpole5 ib16 = -2 * irpole6 * cos(itheta6) ib26 = irpole6 * irpole6 ;printk 1, ib 11 ;printk 1, ib 21 ; also try setting the -1 coeff. to 0, but be sure to scale down the amplitude! asin1 biquad apulse * iamp1, 1, 0, -1, 1, ib11, ib21 asin2 biquad apulse * iamp2, 1, 0, -1, 1, ib12, ib22 asin3 biquad apulse * iamp3, 1, 0, -1, 1, ib13, ib23 asin4 biquad apulse * iamp4, 1, 0, -1, 1, ib14, ib24 asin5 biquad apulse * iamp5, 1, 0, -1, 1, ib15, ib25 asin6 biquad apulse * iamp6, 1, 0, -1, 1, ib16, ib26 afin = (asin1 + asin2 + asin3 + asin4 + asin5 + asin6) outs afin * sqrt(p6), afin*sqrt(1-p6) endin </CsInstruments> <CsScore> ;ins st dur pulseSpd pch pan amp Modes i1 0 12 0 7.089 0 0.7 2 i1 . . . 7.09 1 . . i1 . . . 7.091 0.5 . . i1 0 12 0 8.039 0 0.7 2 i1 0 12 0 8.04 1 0.7 2 i1 0 12 0 8.041 0.5 0.7 2 i1 9 . . 7.089 0 . 2 i1 . . . 7.09 1 . . i1 . . . 7.091 0.5 . . i1 9 12 0 8.019 0 0.7 2 i1 9 12 0 8.02 1 0.7 2 i1 9 12 0 8.021 0.5 0.7 2 e </CsScore> </CsoundSynthesizer>