Would that be the subsonic filter? I would imagine that's what you're talking about. I didn't really pay much attention to the way it sounded with it engaged. I will play with it more later. My next project is removing the bad driver to search for clues.

My Stuff :

M80's
QS8's
VP150
EP800
Denon 4802
Emotiva XPA-3
Samsung BD-P3600
Sharp 65 Inch Aquos LCD