I'm building a home theater and plan to use an acoustically transparent screen with in-wall front speakers. Toole's Sound Reproduction book suggests three to four inches thick of acoustic absorber between the three front speakers. The problem is that this diagram likely assumes these are outside-wall speakers.

Toole's Recommendations

The wall hasn't yet been built, so I have complete flexibility. I'm wondering; should the wall be built completely of drywall and should the absorbing material protrude 3 to 4 inches from the speaker drivers? I'm concerned this will absorb a significant portion of the speakers' direct energy as the absorbing material is directly in between some of the speaker output angles and the listeners.

Or alternately, would it be more desirable only to drywall over the wall cavity where the speakers are installed, and insert the absorbing material into the middle wall cavities without installing drywall on the room interior in those sections?

I haven't seen baffle walls designed like this, but there isn't a lot of literature on the subject.