Fwd: [PD] how to trigger bang's with a period less than 1 milisecond

[Jamie Bullock]

Hi,

On Wed, 14 Jun 2006 10:38:09 +0300
sokratesla <ugurguney at gmail.com> wrote:

> 
> (((# My ultimate aim was producing a pure sinusoid at a frequency of, say at
> 22200 Hz, and here it as it were 150 (= 22200-22050) Hz. in order to make an
> example of Nyquist Theorem. I first tried to use the osc~ object but it
> didn't give the result I expected. 

That's because the example you give here isn't an example of the Nyquist theorem. The aliased frequencies 'fold back', rather than wrapping. It is like the Nyquist frequency is a mirror reflecting the signal's components back into the sub Nyquist range. This can be represented by:


fa = |R*n - fs|

Where fa, is the frequency of the alias of a sinusoidal component fs, R is the sample rate, and n is (fs / R) rounded to the nearest integer.

best,

Jamie