Odp: [sdiy] About that spherical impulse generator...

[Roman]

Don't know if it was mentioned yet, but what about a big sparkle?
Say 2 electrodes 1cm apart, huge capacitor for, say 1kV, and
ignition impulse of several kV to break the air.
It's small object generating very short pulse, so I reckon it should
make omnidirectional Dirac audio response
whadayathink?

Roman

----- Original Message -----
From: Glen <mclilith at charter.net>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Friday, January 09, 2004 9:55 PM
Subject: [sdiy] About that spherical impulse generator...


> There was someone recently talking about building a roughly spherical
> shaped speaker array, for the purpose of capturing the impulse response of
> an acoustic space. I assume that swept sine waves were going to be played
> on the 24 speakers of this array.
>
> What about using a dirac pulse instead? Since the speakers can't follow
the
> transient of the dirac very well, replace them with a spherical array of
> piezoelectric discs. These are cheaper than speakers, have a much better
> transient response, and for the short duration of the dirac pulse, could
be
> driven much harder than they normally would be for a continuous signal. I
> believe that someone said that the speaker beaming issue was worse for
> larger diameter speakers and higher frequencies. Since these piezo
elements
> are much smaller than most speakers, you can pack many more of them on the
> surface of your approximated sphere, for any given sphere diameter. I
would
> think this should reduce the beaming problem a great deal. I know, you
> probably don't think that piezo discs could generate enough volume, but
> keep in mind that there will be MANY of these discs pulsed to their
> absolute maximum peak volume, all at the same time. It only has to be loud
> for an instant. I think it just might work, at least for smaller spaces,
> perhaps not even as small as one would first think.
>
> Does anyone think it's a crazy idea? ...an interesting idea? ...maybe even
> a good idea?  :)
>
>
> later,
> Glen Berry