Cool. I think you and I are on different wavelengths concerning front and rear though-- you say the tiles are on the rear wall, which I'd call the front wall-- I assume you mean rear as in kill the reflection off the rear of the speaker, where as I mean it as the wall behind you when you are listening. Semantics are fun, eh?
I also meant dead not in the anechoic chamber sense, but dead as in the reduced reflection of sound sense.
Either way, looks like you've got it well thought out. That air gap in behind the plywood is a good idea, too- I bet it keeps your neighbor from throwing things at you over the fence.
