At 5:58 AM -0800 1/30/07, umashankar wrote:
>i had been building arrays of small capsules for atleast 20 years
>now. i take a plate of about 6 inches square (it can be smaller) and
>mount five capsules in a kind of irregular cross. there is a central
>capsule, one capsule is half inch away, the next one, at right
>angles, about an inch, the third an inch and half and the last two
>inches. i parallel all the capsules and treat them like one. it not
>only improves the noise figure (by about 12 db i think) it makes it
>surprisingly directional. there is cancellation of sound from any
>angle other than 90 degrees to the plate (the irregular arrangement
>is to meld all the cancellations) and mounting them on a plate gives
>you a very clean boundary layer effect. there is no pick up at the
>back, which also doubles your figure of merit.
>
>umashankar
>
>(we will build one in the forests of karnataka next week)
>
>umashankar
Hi Umashankar--
12dB(A) less noise, compact, easily wired,.. I would love to see a
picture. Enjoy your trip to Karnataka! Rob D.
>
>
--
Rob Danielson
Peck School of the Arts
University of Wisconsin-Milwaukee
http://www.uwm.edu/~type/audio-art-tech-gallery/
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