They might have been electrostatic blocks? Basically a big piezo crystal that expands, as used in some camera focus controls. You need a well regulated high voltage to operate them though. I've never seen anything like that as a bass driver. For ideas to experiment you could check out servo operated bass drivers and the acoustic wave cannon design.
http://www.servodrive.com/basstech7.html http://cardhouse.com/x09/wave.htm
On Tue, 08 Jan 2008 10:55:50 +0900 PSPunch shima@pspunch.com wrote:
Hi all,
I would first like to apologize that this is totally unrelated to Pd. However I figured that this list is the most likely place to find an answer among the communities I subscribe to.
Years ago I used some driver units to playback super low frequencies, down from the inaudible up to probably 100Hz at most. It was more like a chunk of steel designed to mount on any surface expecting it to resonate. These units were also very inexpensive and ran for 10s or 20s of US dollars I think.
Today when I search for driver units of such kinds, all I can find are ones which look more like speaker cones and not exactly what I recall.
Does anyone know of where to look, or keywords pointing to such products? and hopefully places I can purchase them online?
BTW, of course the goal is to drive some of these using PD, inspired by Roman's work using solenoids :)
-- David Shimamoto
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