mc.biquad~
Description
biquad~ implements a two-pole, two-zero filter using the following equation:
y[n] = a0 * x[n] + a1 * x[n-1] + a2 * x[n-2] - b1 * y[n-1] - b2 * y[n-2]
You can specify the coefficients a0, a1, a2, b1, and b2 as signals or floats (if you make the filter explode by making the b coefficients too high, you can recover (after lowering them) with the message, or by turning the audio on and off).
Arguments
a0 [float]
Set the initial value for the a0 filter coefficient. If a signal is connected to the second inlet, the coefficient supplied as an argument is ignored.
a1 [float]
Set the initial value for the a1 filter coefficient. If a signal is connected to the third inlet, the coefficient supplied as an argument is ignored.
a2 [float]
Set the initial value for the a2 filter coefficient. If a signal is connected to the fourth inlet, the coefficient supplied as an argument is ignored.
b1 [float]
Set the initial value for the b1 filter coefficient. If a signal is connected to the fifth inlet, the coefficient supplied as an argument is ignored.
b2 [float]
Set the initial value for the b2 filter coefficient. If a signal is connected to the sixth inlet, the coefficient supplied as an argument is ignored.
Attributes
smooth [int] (default: 1)
Toggles the smoothing of filter coeffient changes.
Common Box Attributes
Multichannel Group Attributes
Messages
int
Arguments
The coefficients in inlets 2 to 6 may be specified by a number instead of a signal. If a signal is also connected to the inlet, the number value is ignored.
float
Arguments
list
Arguments
a1 [float]
a2 [float]
b1 [float]
b2 [float]
clear
dictionary
Arguments
signal
yn = a0xn + a1xn-1 + a2xn-2 - b1yn-1 - b2yn-2.
In 2nd inlet: Amplitude coefficient a0, for scaling the amount of the current input to be passed directly to the output.
In 3rd inlet: Amplitude coefficient a1, for scaling the amount of the previous input sample to be added to the output.
In 4th inlet: Amplitude coefficient a2, for scaling the amount of input sample n-2 to be added to the output.
In 5th inlet: Amplitude coefficient b1, for scaling the amount of the previous output sample to be added to the current output.
In right inlet: Amplitude coefficient b2, for scaling the amount of output sample n-2 to be added to the current output. .
stoke
Arguments
a1 [float]
a2 [float]
b1 [float]
b2 [float]
Multichannel Group Messages
Output
signal
The filtered signal.
See Also
Name | Description |
---|---|
buffir~ | |
cascade~ | |
comb~ | |
cross~ | |
filtergraph~ | |
lores~ | |
onepole~ | |
reson~ | |
svf~ | |
teeth~ | |
Audio Filtering | Audio Filtering |