The best "mass air mass" soundproof assembly seems to have 2 panels. Sometimes you want more panels, for example, to better heat insulate a window. Then you get the "triple leaf" effect that reduces soundproofing.
Problem 1:
You have to soundproof a square opening.
- Opening area = 1 m^2
- Depth = 10 cm
- You must use 3 reflective panels.
- Total panel mass = 10 kg
How do you space the panels and distribute their mass? How does the answer change when there are more panels?
Problem 2:
It's the same as Problem 1, but you get 10 kg of absorptive material. How do you distribute it?
There's also the coincidence effect to consider.
