[PD] phasor to square

[Andy Farnell]

Actually, scrub that, PAF is more complex than AM, its also doing waveshaping
using the windowing function.

Here's an impulse + filter, side by side with PAF and with VOSIM 
so you hear the difference. 

Hear how the filter bank sounds nice but is rubbish and breaks when
you move the frequency, PAF is smoother and thinner, VOSIM is richer
and seems to move frequency the best.


On Tue, 22 Jan 2008 00:25:49 +0000
Andy Farnell <padawan12 at obiwannabe.co.uk> wrote:

> On Tue, 22 Jan 2008 00:46:18 +0100
> "raul diaz" <raul.lete at gmail.com> wrote:
> 
> > Hi Andy, all!
> > 
> > 
> > FOF (formante onde function) is an additive method that uses a periodic
> > > impulse and a bank of tuned resonant filters as exponential sinewave
> > > generators,
> > >
> > 
> > 
> > When you says "bank of tuned resonant filters" are you talk about the
> > spectral effects produces by the FOF envelope, am I wrong?
> 
> 
> No, not the envelope, as far as I know. I see at least two implementations of
> FOF. The first comes from the CHANT vosim (Rodet) which uses stored table
> oscillators (sines) and an exponential decay envelope. It can layer many of these
> together to create a single grain. Vercoe and Clarke both wrote different Csound
> implementations, the cool thing about one was that you could put anything you like
> (non-sine) into the wavetable at i-time to get crazy voices, and the other computed
> the sines so was less flexible but needed no memory.
> 
> The other implementation I am aware of is Cooks (which I presume is in the STK)
> and uses parallel resonant filters. If you hit a highly resonant filter with an
> impulse it rings, so behaves like an exponential decay envelope on a sine wave.
> 
> Same method, similar algorithm, different implementations.
> It's essentially additive/parallel.
> 
> 
> VOSIM (Kaegi) and PAF (Puckette) are two implementations of a totally different
> method, which is basically AM to add sidebands to a sine. The modulation comes
> from a raised window, usually Gaussian, narrowing the window effectively increases
> the modulator frequency and the position of two sidebands.
> 
> It's a while since I read anything about these and there are several 
> implementations so I may be way off. In theory (and no doubt someones done it) you
> can do the same with FM and modulate the frequency of the packet.
> 
> 
> 
> 
> 
> 
> > Or maybe are you talking about a different implementation from the original
> > one by Rodet.
> > 
> > I would know your suggestions about Pd implementation of FOF synthesis.
> > 
> > 
> > Saludos!
> > 
> > 
> > -- 
> > Raul Diaz Poblete
> > *************************
> > raul.lete at gmail.com
> > Barcelona [Spain]
> > 
> 
> 
> -- 
> Use the source
> 
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-- 
Use the source
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