I use an M3 vertical and inverted on top of my 65" RPCRT, but it's still a bit too high for proper localization. I would like to go with two M3s in parallel, but the M3 is way too deep to mount below the screen without sticking out too far into the room.

I could get a W3 to snuggle into an indentation of the cabinet under the screen, but I don't know if a vertical M3 would work well with a horizontal W3, or if the M3 and W3 would even play well together at all.