[PD] Combat aliasing!

[Derek Holzer]

I was thinking about this the other day.... is it possible to have 
aliasing with Karplus-Strong? Because it's a delay line, nothing is 
being played back at any higher rate than it was sampled at, so no 
aliasing should be possible. Right? Math-gurus correct me if I'm wrong.

Otherwise, any signal generator needs to be bandlimited or oversampled:

http://en.flossmanuals.net/PureData/Antialiasing
http://en.flossmanuals.net/PureData/GeneratingWaveforms

Frank Barknecht has some spliced-transition trick he uses as well, I'm 
sure it will come up in a reply or two on this thread as well...

D.

On 3/31/10 6:27 PM, Pierre Massat wrote:
> Hi!
>
> I ve been reading the on-going debate about interpolation for a few
> days, and it just occured to me that i don't how go about avoiding
> aliasing more generally than with band-limited wavetables. If i wanted
> to play a sample at a pitch higher than the original, or if i wanted to
> use a karplus-strong resonator to generate notes, what would be the
> proper way of ensuring that no aliasing occurs? Do people generally use
> low-pass filters with a cut-off somewhere below the Nyquist frequency?
> Or is there a trick that one can use earlier on in the signal path of a
> patch?

-- 
::: derek holzer ::: http://macumbista.net :::
---Oblique Strategy # 139:
"Revaluation (a warm feeling)"