resonxk — Control signal resonant filter stack.


resonxk is equivalent to a group of resonk filters, with the same arguments, serially connected. Using a stack of a larger number of filters allows a sharper cutoff.


kres resonxk ksig, kcf, kbw[, inumlayer, iscl, istor]


inumlayer - number of elements of filter stack. Default value is 4. Maximum value is 10

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.

istor (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.


kres - output signal

ksig - input signal

kcf - the center frequency of the filter, or frequency position of the peak response.

kbw - bandwidth of the filter (the Hz difference between the upper and lower half-power points)

resonxk is a lot faster than using individual instances in Csound orchestra of the old opcodes, because only one initialization and 'k' cycle are needed at a time, and the audio loop falls enterely inside the cache memory of processor.


Written by Gabriel Maldonado.

New in Csound 5 (Previously available only on CsoundAV)