[LAD] Leslie and convolution

Fons Adriaensen fons at linuxaudio.org
Thu Jul 26 20:42:54 UTC 2012


On Thu, Jul 26, 2012 at 08:14:26PM +0200, Robin Gareus wrote:

> On 07/26/2012 07:10 PM, Florian Paul Schmidt wrote:
>
> > It's of course a tradeoff - You need quite a few IRs to make the
> > transitions smooth.. But then it's just a matter of hacking some code
> > around an existing convolution engine..
> 
> You're pretty much describing
>   https://github.com/pantherb/setBfree/blob/master/b_whirl/whirl.c

Crossfading between IRs will not reproduce the Doppler effect
unless the phase response of the two IR that are being cross-
faded is within 90 degrees or so at all frequencies of interest.
Which means you'll need a lot of IRs. So it's more efficient to
separate the filtering and the delay. Once that's done, you can
probably find a parametric description of the filtering in function
of the angle of the driver. It doesn't need to be exact - a lot of
what a Leslie produces is there not by design but by accident.

Ciao,

-- 
FA

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It's also a pipe-dream, founded on self-delusion, nerd hubris
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