I currently have an IB system consisting of 4 15" Parts Express IB drivers in a 2x2 manifold mounted in a side wall toward the front of the room. I'm thinking of re-configuring my HT in a manner that would let me mount the drivers right beneath the screen (no manifold). If I do that, how sturdy of a substrate should I use to mount the drivers. Would 3/4" plywood be enough or should I double that up? The substrate would be screwed to 2x4 studs, though I might have vary the usual 16" OC spacing for even spacing of the drivers.
The Parts Express drivers are a bit old school but I'm inclined to keep them since they seem to produce more than adequate bass in my relatively small HT--and they are already paid for!