Карусель Гельмгольца 2

I attempted to measure the amount of acoustic thrust by placing the acoustic resonator (Christmas tree ornament = spherical Helmholtz resonator) on a precise scale, driving it at its resonance frequency of 386 Hz, and measuring the amount of force (mass times gravitational field strength) as a function of how loud the sound was (sound pressure level in decibels). I managed to measure Newtons of acoustic thrust at 125dB. Not very large, but definitely measurable!