Well, I can't pretend to explain it because I read the manual the same way. But the sub is still very active when I set the 3805 to "direct" or "pure direct" (which is stereo 2 channel - or more correctly 2.1 channel). Still sounds pretty good to me ! We read the manual the same way - but maybe it lies. The sub still gets a LFE signal with my setting (fronts to "large" and sub mode to "LFE").

ken