I mentioned reflection plate drum trigger design VS the seemingly more popular crossbar-and-cone. I thought I'd share some links related to reflection plate design in case anyone wanted to try one.
Yamaha RHP drum trigger dissected
DIY Yamaha RDP style acoustic conversion.
DIY reflection plate acoustic kick
VDrums thread showing a 1990's S&S Industries drum trigger kit dissected.
Hellfire's proposal for a true dedicated 3-zone reflection plate drum trigger using two reflection plates and rim piezo.
Hellfire's Remo practice pad conversion using reflection plate.