vlowres — A bank of filters in which the cutoff frequency can be separated under user control.
asig -- input signal
kfco -- frequency cutoff (not in Hz)
kres -- resonance amount
ksep -- frequency cutoff separation for each filter: the first filter has a kfreq cutoff, the second has a kfreq + ksep and the third kfreq + 2*ksep and so on, depending on the number of filters.
vlowres (variable resonant lowpass filter) allows a variable response curve in resonant filters. It can be thought of as a bank of lowpass resonant filters, each with the same resonance, serially connected. The frequency cutoff of each filter can vary with the kcfo and ksep parameters.
Here is an example of the vlowres opcode. It uses the file vlowres.csd.
Example 1008. Example of the vlowres opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform -odac ;;;realtime audio out ;-iadc ;;;uncomment -iadc if RT audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o vlowres.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 kamp init p4 asig vco2 kamp, 110 ;saw wave kfco line 30, p3, 300 ;vary the cutoff frequency from 30 to 300 Hz. kres = 20 ksep = p5 ;different resonance values iord = p6 ;and different number of filters aout vlowres asig, kfco, kres, iord, ksep aclp clip aout, 1, 1 ;avoid distortion outs aclp, aclp endin </CsInstruments> <CsScore> f 1 0 16384 10 1 ;sine s i 1 0 10 .1 5 2 ;compensate volume and i 1 + 10 .1 25 2 ;number of filters = 2 s i 1 0 10 .01 5 6 ;compensate volume and i 1 + 10 .04 15 6 ;number of filters = 6 e </CsScore> </CsoundSynthesizer>