[PD] pddp keywords

Roman Haefeli reduzent at gmail.com
Mon Apr 2 21:31:22 CEST 2012


On Mon, 2012-04-02 at 11:36 -0700, Jonathan Wilkes wrote:
> >________________________________
> > From: Martin Peach <martin.peach at sympatico.ca>
> >To: Jonathan Wilkes <jancsika at yahoo.com> 
> >Cc: "pd-list at iem.at" <pd-list at iem.at> 
> >Sent: Monday, April 2, 2012 2:04 PM
> >Subject: Re: [PD] pddp keywords
> > 
> >On 2012-04-02 13:45, Jonathan Wilkes wrote:
> >...
> >
> >> One example is the keyword "bandlimited": the definition currently is,
> >> "object that describes itself as
> >> bandlimited"! Thus, I only tagged those objects which called themselves
> >> band limited in their description,
> >> and this obviously has left out many objects. So what is a decent, short
> >> definition for bandlimited?
> >
> >All frequency components are within a specified bandwidth.
> 
> 
> But with something like [creb/blosc~] you don't specify the bandwidth.  Is a 
> 
> different definition being used there?

I guess not. "Band-limited oscillator" in this context means that it
creates a waveform that does not contain any partials (multiples of the
base frequency) higher than the Nyquist frequency, which is half the
sampling rate. It assumes a implicit band-limitation within O Hz and
sr/2 (22050 Hz, if your sr is 44100). 
A plain (non-band-limited) [phasor~] doesn't care about the Nyquist
theorem and happily plays partials well above the Nyquist frequency,
which are reflected on said border and appear as aliases in the audible
spectrum. So to say, a non-band-limited [phasor~ ] suffers from aliasing
effects, which a band-limited or anti-aliased sawtooth generator does
not. 

Roman
  




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