BALL OF SOUND
Construct a low-cost spherical
speaker array. By Michael F. Zbyszynski
Acoustic instruments radiate sound in a wonderfully complex, 360° fashion, while conventional
loudspeakers project a boring spotlight of sound.
You can spend a ton of money on a fancy spherical
audio array, or you can build one for cheap out of
2 IKEA salad bowls and 8 surplus car speakers.
Photography by Michael F. Zbyszynski
1. Cut the hole for the top speaker.
I would love to say that I was smart enough to have
found a speaker and bowl combination that worked
out like this, but it was luck. The speaker fit exactly
inside the rubber ring on the bottom of each bowl,
after I cut along its inside edge (Figure A).
2. Make a template.
Since the hole for the top speaker was the perfect
size, I used it as the template for the other 3 holes.
Trace it onto a piece of paper, and use scissors to
cut out the template (Figure B).
3. Mark the side speaker holes.
Use your paper template to trace the other speaker
holes onto each bowl (Figure C). The holes should
be cut evenly around the sides of the salad bowl. To
make sure they are exactly 120° apart, use a piece of
heat-shrink tubing (or the like) to measure the bowl’s
circumference. Then divide the circumference by 3,
cut or mark the tubing to that length, and use it to
mark where the center of each speaker should be.
For one hemisphere, I centered a speaker on the
handle and measured from there. For the other
one, I started by centering a speaker on the spout.
That way, the speakers are offset when you put the
hemispheres together. Make measurements from