A. Plastic tubing fittings, 2" OD,
push-to-connect (PTC): tee connector ( 1), adapters to 2" male NPT
pipe thread ( 2), adapter to 2" flare
( 1) These are found in the plumbing
aisle at hardware and home stores.
B. Propane tank, 20lb
Photography by Sam Murphy
C. Gas regulator High-pressure
gas regulators such as those used in
high-output outdoor stoves work well if
throttled down. However, the propane
regulator used on a standard gas grill
will work. Note that there’s a safety
device in the regulator that shuts off the
gas if you open the valve too quickly. To
prevent this, open the valve very slowly.
D. Pipe flashing boot (optional)
Sometimes called a “witch hat,” this
conically shaped piece of rubber
is designed to fit pipes of differing
diameter together, so it’s an easy and
secure way of attaching a 2" conduit
or pipe to a larger-diameter speaker.
They’re available at home stores in
the roofing materials aisle.
E. & F. Amplifier and loudspeaker
A small, monaural amp and a 3"
speaker are plenty. You could salvage
an amplified computer speaker
(shown here), or feel free to use
larger old hi-fi equipment.
» Plastic tubing, 2" OD (outer
diameter), 1 roll
» Steel conduit, 2" diameter,
5' length You can use steel pipe
instead, but don’t use plastic
pipe — the heat from the flame
tube will soften and melt it.
» Rubber balloons, helium quality
Helium-quality balloons are thicker
and less likely to leak than regular
» Rubber bands and/or strong tape
» Dimensional lumber, 2× 4, 78" total
length cut to lengths of 12" ( 4) and
30" ( 1)
» Deck screws, 2½" ( 1 box)
» Frequency generator and/or music
sources Pure-frequency audio test
tones can be found online as .mp3
or .wav files. Free or inexpensive
frequency generator applications are
available for personal computers,
iPhones, iPads, and other handheld
computing devices. Any music source
you can connect to the amp will work.
» Electric drill or drill press While a
handheld drill will work, 100 is a lot of
holes to drill!
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