I'm not a newbie to all this and have searched the forums for an answer but I'm tying myself in knots. What is the difference between an amp with a single rear centre output compared to one with 2 centre rears. The way I understand it is that there are no 7.1 DVDs so the only sound you will get from the rears is a single channel split into 2 for 7.1. Is this right. Also, I'm looking to spend between £500-800 on a new amp, probably a Sony, so is there a point shelling out extra for 2 rear channels? I have Mirage AVS200 speakers (100W) at the moment and would need another pair. Any help is appreciated.