One rarely sees this sort of construction in US, and even less as you travel West.
It looks like a sort of "Pressure Cooker" for certain frequencies, likely requiring some sort of "damping" and other shaping measures in order to get even FR output.
OTOH, it is unlikely that there would be much need to boost much of anything.
This is a legitimate tactic, IMO, but quite expense cost/sq. ft. in USA, relative to more "conventional" local construction.
Neighbors should be grateful, however! |