I have an Onkyo 605. Normally I have 5.1 speakers connected but occasionally I borrow a pair of speakers from another room and set up 7.1. I don't currently have any 7.1 sources. I have Pan's Labyrinth on HD DVD which I believe is 7.1 but my only player is the XBOX HD add-on hence I still can't get 7.1. So, I used modes such as PLIIx which, for some discs at least, gives a nice effect. I have just borrowed a PS3 and some BluRay discs for a couple of days to help me decide whether to get a PS3 or other BluRay player. I am playing the TrueHD or other high quality audio tracks so the amp is showing multichannel. Normally it shows 5.1 but it did show 7.1 once which is a bit of a puzzle since the extra speakers are not currently connected. I won't have time to connect the extra speakers and try 7.1 with the PS3 before I must return it. Here's the question. Suppose I get the PS3 and run it in this multichannel mode to get the best quality. If the disc is only 5.1 will I be able to select one of the extension modes to get the extra speakers active? I have read discussion of this somewhere in the forum but I can't find it now. It may be buried in the huge 605 owner's thread. I think that most people said that it could not be done but one person said that it could.