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 pretty 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. It's a perfect job for a 3D printer. Total cost for parts and materials is just under $100. That includes speakers, hardware, wires, cable, plastic filament - everything.
January 16, 2015
I recently made my original SketchUp files for these parts publicly available at this link:
These may be useful to anyone who wants to adapt the design to their own equipment.
The high symmetry of the dodecahedron is amenable to a modular design, and this one consists of four basic parts: the face modules, the vertex plugs, the edge gaskets, and the bezels. The speaker grilles are made from hardware store window screen cloth installed in the bezels using rubber spline and a screen roller tool, just like a residential window screen.
The assembled speaker array weighs 5.6 lbs, not counting the cable, and measures 7.5" across, from face to face, and 8.6" from point to point. The speakers are wired in a hybrid series-parallel circuit that brings the total array impedance to about 10 ohms (again not counting the cable) which should be a comfortable load for most amplifiers.
Non-printed parts ("vitamins")
- 12 pcs Ã— speaker, square, ferrite 3", 8 Ohm, 3W, Jameco SP83W
- 10 ft Ã— instrument patch cable, 18 AWG leads, such as Conquest Sound CS118
- 30 pcs Ã— sex bolt (hehehe), combo truss head, zinc plated, 3/16" barrel, #6-32 Ã— 3/8", Bolt Depot 14285
- 30 pcs Ã— machine screw, combo truss head, zinc plated, #6-32 Ã— 1/2", Bolt Depot 2887
- 60 pcs Ã— split washer, #10, zinc plated, Bolt Depot 3023
- 108 pcs Ã— wood screw, #4 Ã— 1/4", black oxide or finish of your choice, such as McFeely's 0402-PSK
- 13 ft Ã— screen spline, vinyl serrated, 1/8", black or color of your choice, such as Home Depot 3028737
- 3 sq ft Ã— window screen, black or color of your choice, such as Home Depot 3003947
- 36 in Ã— hook-up wire, stranded, 18AWG, white or color of your choice, such as NTE
- 18 in Ã— hook-up wire, stranded, 18AWG, red or color of your choice, such as NTE
- 2 pcs Ã— craft foam, adhesive-backed, 8.5 Ã— 5.5" sheet, black or color of your choice, such as Fibre Craft
- 2 pcs Ã— wire nut, orange, such as Ideal 73B
- 1 cu ft Ã— glass wool, such as Owens Corning PINK
- 6 in Ã— electrical tape
Detailed assembly instructions available here: