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

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).