[PD] Understanding Oversampling

[Frank Barknecht]

Hallo,
David F. Place hat gesagt: // David F. Place wrote:

> I'm trying to understand J07.oversampling.pd.  Is the structure of the
> 3-pole, 3-zero Butterworth low-pass filter specific to the 16x
> upsampling?  Should it be different for 32x upsampling?

I'm pretty sure it should be different. Generally the numbers you put
into the cpole/czero objects of Pd are the coordinates of points in the
complex plane, where the frequencies are mapped to angles of a circle.
The angle PI or 180 degrees corresponds to the Nyquist frequency.

So depending on your samplerate you will have the same angle in the
plane or the same pole/zero point correspond to different frequencies.
For example PI will be 22050 for samplerate of 44100, and 24000 for a SR
of 48000 Hz and then everything else is scaled accordingly.

Ciao
-- 
Frank