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Mzed writes -
Acoustic instruments radiate sound in a wonderfully complex, 360 degree fashion, while conventional loudspeakers radiate in a much more boring, spotlight of sound. You could spend a ton of money on fancy products:Hemisphere from Electrotap
Experimental Meyer Arrayor you could follow these instructions to build a cheap array out of IKEA salad bowls and surplus automotive speakers.
Special thanks and apologies to Dan Truman and the researchers at CNMAT, who's scientific work directly inspired this project.
instructables : Low-cost Spherical Speaker Array - Link.
IKEA! Is there anything they can't do!?!
Seriously, this is a great packaging idea for a fun old speaker idea. You can mess it up with bad speaker selection, but you'd have to work at it.
It works a lot better than you might think.
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Cute, and a fun way to play with cheap speakers. This isn't new (although the Meyer project does include some new ideas with active phase control). There were commercial polyhedral speakers being sold in the 1970s.
This idea eventually occurs to everyone, with the idea being true omnidirectional radiation. Problem is that a spherical array of full-range speakers doesn't give you omnidirectional radiation, but rather a very complex multi-lobed radiation pattern. It's also very hard to hold the cabinet motionless, which is a requirement for preventing all kinds of doppler effects.
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UPDATE: It was the Design Acoustics D-12, and it came out in the late 70s. Julian Hirsch raved about it, but almost no one else did. They later switched to more conveentional speakers.
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The Meyer array is really cool for a number of reasons. First, it receives 120 channels of audio over ethernet, and does the d-to-a and amplification itself. Also, none of the speakers are acoustically coupled, which is a problem in my array.
On the software side, CNMAT has done a lot of work with the filter mathematics to make radiation patterns by leveraging the interference between individual drivers. It can do some pretty tight beaming.
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