Thanks Leon, my surrounds are currently dipoles, situated about 1.5-2m close behind me. My couch is close to the back wall. I'm thinking of adding surrounds, which will then mean that my current surrounds will function as rear surrounds. My set-up will then be:
Surrounds, about 2m in front of me. To keep them inconspicuous, I'm think of mounting them close to the ceiling at about 3.2m high.
Rear surrounds. I keep my current surrounds, which will now become rear surrounds, about 2m to the left and right of my listening position, 1.8m off the floor.
My question is then, will mounting the surrounds in a high position (3.2m high, and 2m in front on the left and right walls) be a poor position, seeing that the rear surrounds are 1.8m above the ground and 2m behind me? Or can I compensate for the differing heights by adjusting the speaker volumes and distances, i.e. calibrating the system to compensate for the differening positions. I'm also limited here by what my wife approves

. So, even if the positions are not ideal, it's a compromise between adding 2 extra speakers, without the 2 new additional speakers being too obtrusive.