19 lines
524 B
Plaintext
19 lines
524 B
Plaintext
# This shows how to create a lowpass biquad filter using the IIR filter type
|
|
# The result should be equivalent to the command
|
|
# Filter: ON LP Fc 3000 Hz
|
|
|
|
Eval: freq = 3000
|
|
Eval: Q = 1/sqrt(2)
|
|
Eval: omega = 2 * pi * freq / sampleRate
|
|
Eval: sn = sin(omega)
|
|
Eval: cs = cos(omega)
|
|
Eval: alpha = sin(omega) / (2 * Q)
|
|
Eval: a0 = (1 - cs) / 2
|
|
Eval: a1 = 1 - cs
|
|
Eval: a2 = (1 - cs) / 2
|
|
Eval: b0 = 1 + alpha
|
|
Eval: b1 = -2 * cs
|
|
Eval: b2 = 1 - alpha
|
|
|
|
Filter: ON IIR Order 2 Coefficients `a0` `a1` `a2` `b0` `b1` `b2`
|