I calculated if you drill two 3/4" holes into an M2, you end up with resonances at 583 Hz, 782 Hz and 934 Hz. Can you hear them?
_________________________
A-LFR/1000-8/500v4x2 coming
1000-2,3,1500-3
100,160,QS10x2,800,M5,M3,M50 v4
had v2
Air N2 (someday)