This is the same as Ringz , except that it has a constant gain at 0 dB instead of being constant skirt.
It is a two pole resonant filter with zeroes at
Based on K. Steiglitz, "A Note on Constant-Gain Digital Resonators", Computer Music Journal, vol 18, no. 4, pp. 8-10, Winter 1994.
The input signal.
Resonant frequency in Hertz. WARNING: due to the nature of its implementation frequency values close to 0 may cause glitches and/or extremely loud audio artifacts!
Bandwidth ratio (reciprocal of Q). rq = bandwidth / centerFreq.
The reciprocal of Q is used rather than Q because it saves a divide operation inside the unit generator.
Output will be multiplied by this value.
This value will be added to the output.