I have a room 14 wide by 18 feet long. I want to set up 7.1 system. However I am not sure what I should do with the side surrounds. The reason being is my room only has three walls, front wall, right wall (as viewed from the sweet spot), and rear wall. Can I mount the side surrounds to the 8 foot ceiling. I will mount the rear channels on the rear wall but I am not sure what to do with the sides.