Axiom Home Page Forums General Discussion Home Theater Merging side surround channels with rear-ch

Newbie in this forum. Planning to buy a BluRay player with 7.1 analog audio outputs, but my audio system is only 5.1-ch capable. I use an old 5.1 Yamaha receiver as preamp to accept the decoded 7.1 analog signal from the Bluray player, then the signal is sent to an Adcom amp. I want to use the Bluray player to decode lossless Dolby True HD and DTS-HD, but then I would lose the rear-channel information since I only have a 5.1 setup. My question is:
What is the procedure to merge the side-channels with the rear channels (SL+SBL and SR+SBR)? I have read about y-splitters but don't know exactly how to go about it. For those who have done this, exactly how did you go about it without having any drastic side effects? Directly connect a y-splitter onto the Bluray player's analog out then connect the merged output to the preamp's rear surround input? Appreciate your advise. Thanks!

Y-splitters for RCA jacks are just that, splitters. They can't be used to combine to outputs into one input.

It'll be up to the player as to if it can be configured to have the surround back outputs disabled, and if it mixes them in with the side surrounds.