There was a fella that posted a corner system a while back - it used a 15 in a sort of a cube with the lower back corner cut off to form a baffle surface. It looked like a cube stuck in the corner, maybe a couple of inches out. I emailed him back when I remembered who he was, but got no reply. Anyway, if it works on the floor/wall boundary, it should work on the ceiling/wall boundary too, especially if you're not talking huge power. Terry Caine ("Bigger is Better" project) talks about liking the ceiling because it hasn't got furniture in the way.My own experience with multiple small ceiling-corner speakers at Storrowton Tavern is all positive. Very nice bass with little effort - just BR boxes stuffed up into the corners with 1354s in them. Horn reinforcement of the bass is obvious. It's out of your way, but if you come over to 91 instead of taking 84 to Steve's we could thrash them for a bit before the lunch rush.
John