I'm considering CBM-170SE for front LRC of a 5 channel system with AVR. The TV sits on a 3 shelf stand. Will be listening to music also. The front of TV is 18" from the wall. If I place the front of speakers in line with the front of the TV the rear ports will be about 8" from the wall. Is this acceptable? Is it acceptable for the center speaker to sit on its side since the shelf that is just below the TV is only 10" tall?