Attempt 1: Pink Balloon

Our goal was and still is to achieve really sweet examples of cymatics. Wikipedia defines cymatics as "the study of wave phenomena. It is typically associated with the physical patterns produced through the interaction of sound waves in a medium." We had seen examples of this in our Acoustics Labs, but we sought for even cooler examples of this. We were particularly inspired by a video by Hans Jenny, "Cymatics: Bringing Matter to Life Through Sound" available here, & a highly informative website for DIY Cymatics.

Our set up was pretty simple. We borrowed a oscillator from Mathew Deady (holler), hooked this up, via some broken RCA cables, to my Mackie mixer, and then hooked this up to an amplifier.

We decided it “best” to take apart a small guitar amplifier of mine, a cheap Fender Champ. With the grill and speaker taken out we arranged the amplifier so that the speaker could rest inside the hole that it used to be mounted behind.

(What have I done?!)

This way, we could stretch the balloon over the speaker, duct tape all cracks and holes in the cabinet of the amplifier, and, theoretically, any substance placed on the balloon would either vibrate in a standing wave, or fall off of the speaker onto the amplifier’s surface. We hoped that this would keep things neat.

It looked pretty sweet. We figured we were ready to go.

Almost immediately however, we realized that solids, when placed on the balloon, reacted too strongly. The salt did seem to gather in certain places, but we never got a stable pattern out of a standing wave. Even at extremely low frequencies with very small amplitudes, the salt seemed overly excited.
It was time to reconsider our vibrating mediums.