At normal listening distances, an array of twelve speakers arranged on the faces of a dodecahedron is a very good approximation of a point sound source, and the sound waves it produces are very close to perfectly spherical. A dodecahedron speaker can be a useful tool in acoustics research, and is definitely a fun toy to pull out at parties. They are available commercially, but very expensive. Some people build their own, but the odd compound angles and the high degree of accuracy and precision required in the parts make for challenging work with manual tools. But it’s easy for a 3D printer.
If you have a RepRap, MakerBot, Up!, MakerGear, Ultimaker, or other suitable fused-filament printer, you can print and build this speaker for just under $100 in parts and materials. That includes speakers, hardware, wires, cable, plastic filament–everything.
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I have made a bunch of dodecahedrons using just a compound miter saw. After those exercises I also made a little jig for the table saw to get both angles correct (and it also works on the miter saw). I can cut out all 12 pieces in whatever size pretty quickly, then glue them up (blue tape for “clamps”!), some sanding and put on a little finish, and yer good ta go! If they are going to have any sort of rough use, glue up 2 halves, reinforce the joints, then glue up the halves.
I also tried to make a rhombicasidodecahedron (I think I spelled that right) that has 60 or 70 facets in 3 or 4 different shapes (it’s been a while since I did that) but it was very difficult to get every piece with the proper edge angles. I did cut the shapes on my CNC machine, but had to do the edges by hand. It looked sorta cool but did not fit together real well.