ooooh, I like that test harness. Neat!
Also important is whether the material has an obvious resonance frequency. That’s killed a couple of materials, including some really interesting ultra-light carbon fibre material I tried. (But didn’t photograph. My loss.) I didn’t expect that to have a ring but it really did.
I’m gonna build a base-of-styro-cup assembly hopefully today. I’ve figured out a mounting system to try that… wow I’m just really hoping it works, because it’ll be awfully cool. 😀