Quote:
Originally Posted by petertjed  Hi Andre,
I intend to build a room in a room, and would like to build it with a double leafe system, mass air mass. How big does the airgap has to be? |
There is no acoustic minimum. It works out to 3.5" between the leafs with standard 2x4 construction
An other question is if i can use the concrete wall(25cm thick) between me and the neighbours as the first mass? so it would become:
concrete wall - rockwool- air rockwool - drywall
ytong - rockwool- air rockwool - drywall[/QUOTE]
That construction is a triple leaf; bad for low frequency isolation.
As far as rockwool goes, use the standard wall insulation, filling the cavity, but not compacting the material.
Andre