I was doing some listening to music in 2 channel mode the other day when I noticed that on "2 channel stereo" setting, things just didn't sound right as compared to "2 channel direct stereo". The only difference according to the owners manual is that in "2 channel stereo", bass management is applied and the sub continues to run, as opposed to "2 channel direct stereo" which sends a full range sound to just the 2 mains. The weird thing was that in "2 channel stereo", the mids and highs seemed muffled, like the sound was coming from a hollow box, but in "2 channel direct stereo", the mids and highs were crisp and clear. After a bit of tweaking in the setup menu, I realized that the parametric eq from the YPAO auto-setup was applied to "2 channel stereo" but not to "2 channel direct stereo". I turned off the parametric eq and WOW, what a difference in all areas. In Dolby Digital, DTS, Pro Logic, all the music settings, everything was much more detailed. In my room, it seems the parametric eq was really taming the highs too much, making it sound like THX processing where the highs are rolled off, but worse. No more YPAO for me. It's a good feature for setting levels and distances, but for everything else, it's just a starting point. This has made a HUGE difference in the sound of my setup. Thought I'd pass it along for all the other Yammy owners out there.