Axiom Home Page Forums General Discussion Advice from Axiom Owners Multi channel analog with 3.1 system vs Optical

Hi guys, I'm confused about this (as well as many other things)! When using Multi channel analog inputs on a 3.1 system from Samsung BD C6500 to an old Onkyo R520 will I be able to receive all surround channels through just the fronts, center and a subwoofer by setting surrounds to none in the BD player? Or am I better off using the Optical connection (the Samsung has no other options except HDMI which the Onkyo dosent have) and letting the receiver process the PCM to some type of surround?

I really depends on how the BD player, and receiver both handle down mixing. I'd be more likely to believe that the receiver would down mix the rear channels into the fronts, but some BD players do it too. Only way to know is to check the manual (if it is documented at all), or play a test disc that has 7.1 audio tracks and make sure nothing goes missing.

If you deliver PCM over optical it will only be two channels. The only way to get multi-channel over optical is with a lossy bitstream. If the BD player does a good job decoding, and down mixing the lossless audio then the analog connection may yield better sound quality. That's too if the receiver doesn't try to do any fancy processing of its analog ins.

Thanks for the reply, the manual is of little help other than to add to the confusion, there is a speaker setup menu in the BD that allows you to enable, disable and set speaker size when using analog output. Do you think it is safe to assume that when disabling the surrounds the BD will compensate and direct that info to the fronts?

It isn't safe to assume either way, as it varies from player to player. The only way to know for sure is to try, and listen.

On newer players it is more likely that they do preserve the disabled channel's information and mix it into the front. Some will mix it out of phase though (so a Prologic processor can re-extract it).

Thanks for your help, looks like the only way to know for sure is trial and error.