Speaker settings for surround speakers depends entirely on the speakers. If your fronts are full range, run them that way. Using the 80hz crossover is for small speakers with no bass. You hand the bass off to the sub because the speakers aren't capable of hitting the proper notes. Personally, it's probably user dependant. If it does what you say, I'd enable it, and see if you like it. I would think it would boost bass, which may or may not sound good with your selected headphone. I'll have to try this!