Finally finshed the tower box, was much more labour intensive than I first anticipated.
Anyway, the box holds a pair of 6x9's & a pair of 6&1/2's facing back to wards the rider. I have made the mounting ring angled up towards the sky by about 15º so when the boat is on plain & riding a bit nose high they will point at the rider rather than the water directly behind the boat. Also the 6&1/2's are offset by 12º to point outside the wakes for when your cutting out.
On the bottom side of the box I have another pair of 6x9's firing directly down into the boat, the mounting ring is aggresively slanted to make the speaker mount parallel with the floor. Each speaker compartment is an individual chamber. It's off to the painters now to get sealed & top coated.
I've got some photos of various stages of manufacture if anyones interested.