21.3.1 Low-pass filtering
The lowpass
command applies a simple first-order lowpass RC filter
to a signal or audio clip.
-
lowpass takes two mandatory arguments and one
optional argument:
-
A, an audio clip or a real vector representing the sampled
signal.
- c, a real number specifying the cutoff frequency.
- Optionally, r, a samplerate (by default 44100).
- lowpass(A,c ⟨,r⟩)
applies a simple first-order lowpass RC filter to input data and returns the result.
Example
To generate a synthetic signal, enter:
| f:=unapply(periodic(sign(x),x,-1/880,1/880),x):;
s:=apply(f,soundsec(3)):; |
Then:
| playsnd(lowpass(createwav(s),1000)) |
Output: the sound of the periodic signal after applying a lowpass RC filter with cutoff at 1000 Hz.