@Eli Vatsaas Google "images Ruben's tube". Do a little reading then put your creative thinking cap on and let your imagination run wild. Consider a four or six
foot length of schedule 40 4" ID
PVC pipe with thin plastic or rubber sheeting tightly sealed around both ends and a row of 1/8 inch diameter holes drilled in a straight
line from end to end with the aid of a V-block in a drill press to keep them in a straight and pretty, equally spaced,
line. Add gas from a gas valve on your physics teacher's
desk and modulate the wave with a four inch
speaker tightly sealed outside the plastic or rubber sheeting on one end of your tube. Consider playing a mix of pure
sine wave tones at a variety of amplitudes interspersed with some of your favorite music. If you manage to pull this off PLEASE post a few photos or videos of your efforts. I suspect you can make this work satisfactorily without needing to insert tubular metal inserts in the row of parallel holes by beginning your holes with a 1/16 inch
bit and gradually incrementing each hole's diameter up to achieve a clean through-hole minus any burs or fracturing of the edges on the inner wall of your
PVC tube.
Toodleoo!
Ron Hebbard