[sdiy] Speaking of the Elektor Vocoder (and the Korg Vocoder)

[jbv]

anthony,

(I'm jumping back into this thread without reading the few past posts and may
have
missed some details)

>
> That is exactly what I was saying. If you had 100 or even 1000 fixed
> badnpass filters with high enough Q's and had bar graph meters or
> what-have-you on each one, the result would be a spectral analysis much like
> what the Fast Fourier Transform algorithm would yield.

well, from an analysis point of view you might be right (although I've read a
few times
that mathematically speaking, each band of an FFT was totally different from a
narrow
BPF with high Q), but from the re-synthesis point of view, I'm not sure... I've
made
several experiments with realtime FFT / iFFT, and especially by setting the
amplitude
of all but one bands of an FFT to 0 and re-synthesing the signal (actually only
1 band)
via iFFT, and the result is... well... some kind of distorted sound, much
closer to what
you'll get with a ringmod than a narrow BPF... the 1 band iFFT output actually
had no
harmonic relationship with the input signal, when the output of a narrow bpf
does...
I guess there's a mathematical explanation for this...

JB