Comb delay line with no interpolation. See also CombLwhich uses linear interpolation, and CombC which uses cubic interpolation. Cubic and linear interpolation are more computationally expensive, but more accurate.
This UGen will create aliasing artifacts if you modulate the delay time, which is also quantized to the nearest sample period. If these are undesirable properties, use CombL or CombC. But if your delay time is fixed and sub-sample accuracy is not needed, this is the most CPU-efficient choice with no loss in quality.
The feedback coefficient is given by the equation fb == 0.001 ** (delay / decay.abs) * decay.sign where 0.001 is -60 dBFS.
| in |
The input signal. |
| maxdelaytime |
The maximum delay time in seconds. Used to initialize the delay buffer size. |
| delaytime |
Delay time in seconds. |
| decaytime |
Time for the echoes to decay by 60 decibels. If this time is negative, then the feedback coefficient will be negative, thus emphasizing only odd harmonics at an octave lower. Large decay times are sensitive to DC bias, so use a LeakDC if this is an issue. Infinite decay times are permitted. A decay time of |
| mul |
Output will be multiplied by this value. |
| add |
This value will be added to the output. |
// These examples compare the variants, so that you can hear the difference in interpolation
// Comb used as a resonator. The resonant fundamental is equal to
// reciprocal of the delay time.
{ CombN.ar(WhiteNoise.ar(0.01), 0.01, XLine.kr(0.0001, 0.01, 20), 0.2) }.play;
{ CombL.ar(WhiteNoise.ar(0.01), 0.01, XLine.kr(0.0001, 0.01, 20), 0.2) }.play;
{ CombC.ar(WhiteNoise.ar(0.01), 0.01, XLine.kr(0.0001, 0.01, 20), 0.2) }.play;
// with negative feedback:
{ CombN.ar(WhiteNoise.ar(0.01), 0.01, XLine.kr(0.0001, 0.01, 20), -0.2) }.play;
{ CombL.ar(WhiteNoise.ar(0.01), 0.01, XLine.kr(0.0001, 0.01, 20), -0.2) }.play;
{ CombC.ar(WhiteNoise.ar(0.01), 0.01, XLine.kr(0.0001, 0.01, 20), -0.2) }.play;
// used as an echo.
{ CombN.ar(Decay.ar(Dust.ar(1,0.5), 0.2, WhiteNoise.ar), 0.2, 0.2, 3) }.play;