Very good, 317(lots of inputs and outputs back there, eh?). As John hifi commented, set the bass output to sub only, so that the sub is responsible for the frequencies which it handles best and relieves the mains from some of the lowest bass burden. Some prefer to use the setting called "both", "plus", etc., which makes the mains run full-range(with the sub duplicating that lowest bass)and say that the sound is "fuller", but "full"(whatever that means)isn't necessarily good, and for more accurate sound keep the bass responsibilities divided. Enjoy.
