I have the Mission M72 home cinema speaker set, which comprises of M72 mains, M7C1 centre and M7DS bipole rears. First question: Due to the layout of my room, I can only place the M7DS rears high up close to the ceiling. Before I invest in adjustable brackets, is it advisable to have those speakers angled downwards (towards the listener) if they're position high up, or should I leave them positioned flush against the wall? Second question: My AV amp is a Denon 2802 with 6.1, so of course I'm planning to so something about getting an aditional speaker for the 6th (rear centre) channel. Do I get just one speaker (what the amp seems to be made for) or somehow try to connect two speakers into that speaker output? And what type of speakers should I get? I read somewhere not to use two bipoles for centre-rears or that makes the overall surround effects too muffled. They suggest using bookshelf speakers. Would using two rear speakers sound too much mono at the back? Or will using a songle bipole be a good balance? Suggestions please.