resonx — Emulates a stack of filters using the reson opcode.
resonx is equivalent to a filters consisting of more layers of reson with the same arguments, serially connected. Using a stack of a larger number of filters allows a sharper cutoff. They are faster than using a larger number instances in a Csound orchestra of the old opcodes, because only one initialization and k- cycle are needed at time and the audio loop falls entirely inside the cache memory of processor.
inumlayer (optional) -- number of elements in the filter stack. Default value is 4.
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.
asig -- input signal
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)
Here is an example of the resonx opcodes. It uses the file resonx.csd.
Example 901. Example of the resonx opcodes.
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 resonx.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 ; unfiltered noise kenv linseg 0, p3*.5, 1, p3*.5, 0 ;envelope asig rand 0.7 ;white noise outs asig*kenv, asig*kenv endin instr 2 ; filtered noise kenv linseg 0, p3*.5, 1, p3*.5, 0 ;envelope asig rand 0.7 kcf line 300, p3, 2000 afilt resonx asig, kcf, 300, 4 asig balance afilt, asig outs asig*kenv, asig*kenv endin </CsInstruments> <CsScore> i 1 0 2 i 2 3 2 e </CsScore> </CsoundSynthesizer>