[sdiy] ot: rotating speaker simulation or stupid approach

[Peter Grenader]

There is always Cycling 74's and Rocket Science's Orbit Doppler effect plug
ins, both do an excellent job of what you're talking about here.

I know....it's software, but sometimes you just want to zip off the top of
frozen beef stew, stick in the microwave and call it dinner.

Czech Martin wrote:

> I can record the transfer charactericstic of a loudspeaker with some
> microphone in some room (the impulse response, if you like).
> I can repeat that, turning the speaker a few degrees of axis.
> I can do this , say for 23 steps of 15 deg to make a full circle.
> I must be carefull in order to get the right time shift for
> each impulse response vs. all the others.
> I think the impulse response will be not too long, perhaps
> some 10ms.
> 
> So I get a picture of what happens when the speaker is turned,
> the reflexion pattern changes, etc.
> 
> Now I can take some signal and convolute it with those 23
> inpulse responses. Then I can interpolate between those
> impulse responses when doing play back, in order
> to simulate all the positions between two 15 Deg
> measurements. 
> 
> This could give a good approximation of a rotating
> speaker, though computationaly it could be more effective.
> Since all the phase information is preserved,
> even the Doppler effect should be visible.
> I guess that if the grid of angular position would
> be fine enough, this should work perfectly.
> 
> What problems will arrise, if I do it only with
> 15 Deg samples?
> 
> And another question:
> Has someone heard or read about a circular array of fixed speakers
> in order to simulate a rotating speaker?
> I mean N VCAs and N amplifiers together with N little fullrange speakers,
> with some control that will stear the speakers in a circular fashion.
> I think this would be a hardware implementation of the first idea,
> avoiding any rotating or heavy parts.
> 
> ??
> 
> 
> Martin Czech
> 
> 
> 
>