The T2's are the new in wall version of the on wall system. You are correct, they are the M2 but actually in the wall. They don't offer the W3 as of yet.The problem with the room is I have a very open floor plan. Nothing is sealed off, the room itself is average 16x18 but it flows into my whole first floor which is probably 40x60x7. The room has no real enclosed area. So I figured the DP500 would seal the room.