I am interested in using three R-3800-W II In-Wall Speakers for my front, center, and left in my new home theater, but I am unsure of placement on these speakers. The room is a finished space over my garage, so the space has sloped ceilings. The wall they will be mounted in is an odd shape (hexagon)due to the sloped ceilings. The floor measurement is 10'6", the knee wall is 5', the slope is 4'8" at 49.6 degrees, and the flat part of the ceiling is 3'5". My TV is 50", but I plan on getting a larger one in the future. Can you please give me advice as to where to mount these speakers?