Geometry in audio.

Also look into "golden ratio", which is something like 0.619. Fold it in half, and you get it again. Play poker? That card is a golden ratio. It's also found in ancient architecture like the Parthenon.

There are suggestions that it is the perfect shape for a listening room. Something about minimal reflections or standing waves.

jh

Design Acoustics' D-12 was always one of my favorite designs. A dodecahedron speaker (in theory, it was supposed to mimic a pulsating sphere) from the early seventies. It had a 10" downward firing woofer, a 5" upward firing midrange, and nine tweeters on all but one of the remaining faces (which contained the woofer port).

I have not been able to locate a photo of one yet, but do a Google search for dodecahedron speaker. There are other companies using this design.

Can't get anymore pyramid shaped than this: http://www.acoustic-reality.com/tetrasite1.htm