Thanks for that. And it does this properly? I ask because when doing this with analogue 5.1 outputs you can ask the blu-ray / HD DVD player to do this (ie set centre speaker to 'none') but the sound is terrible - the players clearly don't send the centre channel info to the fronts. I just wanted to check that HDMI receivers do a decent job with HDMI audio - I imagine they do but it's nice when someone confirms it!
Thanks again
I ran my 605 with no centre for a long time. If the centre was not detected when you last ran Audyssey (the set-up program) then it remembers that there is no centre and redistributes the sound to the left and right. There is no delay. I did not do anything in the players.
It can sound good if your front speakers are good and well positioned. I have nice floor standing Tannoy R3s just either side of the panel and their speakers are about mid way up the screen. Stereo imaging was good and characters did sound like they were coming from where you saw them.
I got a centre recently mainly to shut up all the people who said to me: "The centre is the most important speaker" or "you won't get any dialogue if you don't have a centre". Some things do sound a bit better with the centre but I am not sure that everything does and I think that some things actually sound poorer.
What I have considered, but not yet tried, is temporarily removing the centre without running Audyssey. If I just removed it then I expect that I would get no dialogue but the plan is to pop into speaker configuration and tell the 605 that the centre is not there. I expect that this would work.
Similarly my rear surrounds come and go (they are not permanent, I borrow them from another room occasionally). The next time that I do it, I plan to note the speaker settings that Audyssey uses so that in future, I don't need to run Audyssey (it takes about 10 minutes).