reson — A second-order resonant filter.
iscl (optional, default=0) -- coded scaling factor for resonators. A value of 1 signifies a peak response factor of 1, i.e. all frequencies other than kcf are attenuated in accordance with the (normalized) response curve. A value of 2 raises the response factor so that its overall RMS value equals 1. (This intended equalization of input and output power assumes all frequencies are physically present; hence it is most applicable to white noise.) A zero value signifies no scaling of the signal, leaving that to some later adjustment (see balance). The default value is 0.
iskip (optional, default=0) -- initial disposition of internal data space. Since filtering incorporates a feedback loop of previous output, the initial status of the storage space used is significant. A zero value will clear the space; a non-zero value will allow previous information to remain. The default value is 0.
ares -- the output signal at audio rate.
asig -- the input signal at audio rate.
xcf -- the center frequency of the filter, or frequency position of the peak response.
xbw -- bandwidth of the filter (the Hz difference between the upper and lower half-power points).
reson is a second-order filter in which kcf controls the center frequency, or frequency position of the peak response, and kbw controls its bandwidth (the frequency difference between the upper and lower half-power points).
Here is an example of the reson opcode. Play reson.csd
Example 897. Example of the reson 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 realtime audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o reson.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 0dbfs = 1 nchnls = 2 instr 1 asaw vco2 .2, 220 ;sawtooth kcf line 220, p3, 1760 ;vary cut-off frequency from 220 to 1280 Hz kbw = p4 ;vary bandwidth of filter too ares reson asaw, kcf, kbw asig balance ares, asaw outs asig, asig endin </CsInstruments> <CsScore> i 1 0 4 10 ;bandwidth of filter = 10 Hz i 1 + 4 50 ;50 Hz and i 1 + 4 200 ;200 Hz e </CsScore> </CsoundSynthesizer>
A musical example featuring the reson opcode: Play ResonPluck_Cucchi.csd by Stefano Cucchi.