Theory 006/Acoustics & Vibration
Insulation Fails at Coincidence
The claim
Building panel insulation collapses at a coincidence frequency set by panel mass and stiffness, so a heavier panel can insulate worse in a band.
01The mechanism
At coincidence the bending wavelength matches the airborne wavelength, and the panel becomes transparent to sound.
02Predictions
- P1Insulation should dip at a predicted frequency.
- P2Stiffening should shift the dip.
03Refutation
Monotonic improvement with mass would remove the coincidence dip.