Looking for a little guideance on where to place LCR ( height and width ). Ive got a 17' x 29' room where the screen is on the short wall which is bumped out 2'. My screen will be roughly 91" wide and start 42" off the floor. Ive got all the same monoprice 8" in walls to put behind my screen. My question is how high off the floor and at what spacing left to right?