Well, I added an M-100 to the center of my M80s. I'll report on the effect once I get it all hooked up & calibrated.

It's an unusual setup as the Oppo 105 will be connected directly to the power amps. All distances (phase) and levels will be set by ear using the Oppo's controls. I do have a preamp, but it's analog stereo only. I'll be using its "HT-bypass" mode for movie & surround audio listening.

My opinion is worth exactly what you're paying for it!