Mad Science/FloatingDroplets

Equipment

• 3.75" midrange speaker from old JBLs. Back labeled 104 H-z. DC resistance about 7 ohms
• Denon home theater amp
• Top from vitamin tub, 4.72" I.D., threaded, 0.83" deep
• Function generator program on jbash's Nexus 6P
• Rubber bands and paper clips
• Speaker wire
• Syringe with red blunt needle (fine gauge; maybe 22?)

Setup

• Run rubber bands between corner holes of speaker.
• Use paper clips in the middle of the bands to hook down the sides of the vessel.
• Wire up the obvious audio path (used the "CD" input on the amp)
• Set up function generator for sine wave
• Output volume on the 6P was just short of maximum.
• Amplitude on the function generator channel was 95 percent

Had to turn volume up surprisingly high. Speaker probably wasn't responding in the range we needed. May have damaged speaker. Try woofer next time?

Tap Water

• Maybe-half-an-inch of water
• Ramp amp volume up to -7dB or so
• Drip in small drops with syringe (maybe 2mm drops?)
• Best result at 59.537 Hz
• Not bad down to maybe 55
• 118 "wanted to work*
• Maximum water drop persistence maybe 2-3 seconds
• Best results when significant visible standing waves, but maybe not *extreme* ones
• Higher volume reaches point of diminishing returns

Even half a hertz makes a difference...

Canola Oil

• Less oil than water
• Same method as water
• Best results at 33.471 Hz
• Longest drop time probably 15 seconds or longer (hard to tell with multiple drops; could have been a minute)