Hi JohninCR,
I reckon your baffless setup is brilliant.
My only comment is that there could be a small light weight baffle resting on the floor, and resting on the flange of the driver- airtight and coming up to the level of the left to right diameter of the 15".
Not only will this give full floor reinforcement, but it helps with frequency response flatness, in the experience I've had doing mock-up baffles.
I'd use my (controversial) 3 ply or similar resting baffle, completely wrapped (including the sides) in either thick felt, or as I do, foam carpet underlay.
As someone else on this forum says, there is a lot of work to be done yet on OB design.
David
