Interesting question. The in-wall speakers appear to be sealed at the back so as long as the sides of the cabinet aren't touching the foam I wouldn't expect a noticeable impact to the sound.

That said, I have zero experience with ICF walls so take this with appropriate grains of salt.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8