I think the problem was the fact that on the speaker configuration screen I had the TRIM settings on 0. I set them to the exact trim setting I have on the 990. Once i did that the multi-channel came on.
I wouldn't have expected that to matter. If it's working, though, so be it. If you want to play around more, you might try setting the trim settings in the BDP-93 to 1dB all the way around and see what that does.
However I have a question.
I have the Oppo 93 multi-channel and the optical connected. I have Two Mains, two subs,two surrounds and one rear surround. When I am using the Optical setting all speakers are operating, but when I have the 7.1 direct for multi-channel setting on the rear surround does NOT operate.
The multi channel sounds awesome even without the rear surround operating.
I believe I have it connecting correctly but can you explain?
The rear surrounds will only work using the 7.1 analog connections when the source includes rear surround channels. Unlike the Model 990 (which has the Pro Logic IIx, Dolby Digital EX, and DTS NEO:6 processing modes), the BDP-93 does not offer an option to apply matrix processing to 5.1 sources to generate back surround channels. Thus you will only hear the rear surrounds with Blu-ray discs that include 7.1 tracks.