I've been debating installing in-wall speakers on an exterior basement wall for a home cinema, and I see problems with every solution.

Naive approach
--------------

Cut out a section down to the concrete and simply install the speaker.

The problem with this, is because I live in a cold climate the vapor barrier is on the inside of the wall, and would be cut and compromised along each place.

Vapor barrier box
-----------------

The next idea was to install a vapor barrier box, allowing me to preserve the vapor barrier, and still install the speaker.

The problem with this, is that in wall speakers are expecting a wall cavity to serve as a loudspeaker enclosure (and can actually benefit from existing insulation in the wall using it to absorb the unwanted waves within the cavity). I expect it would compromise the speakers quality enough to not be worth the effort of installing.

---

Has anyone else solved this problem already? Or is the idea of in-wall speakers just not feasible on exterior walls?