I have some Wharfedale Diamond DFS-18 Rear Speakers and need to get them on the wall. The problem I have, they are both mounted on the rear wall, but one of them will be very close to a side wall (probably 10cm away). Is this ok? or will sound quality suffer? If I bring it into the room more, then they won't be directly behind me properly.. and they'll be close together. They are already too close together anyway according to the manual but it can't be helped. (Only be about 1.8m - 2.0m apart..) Thanks for any help.