I have had my BK XLS200 DF sub for a few years now connected to my Onkyo 605 amp. It was working very nicely until recently I moved house and had to set up the whole thing again. I did the Audyssey calibration through my amp. I have noticed though that when my sub is on it does this low thrumming vibration noise all the time. When I touch the membrane it is constantly vibrating too. Anyone knows what is causing this? Also since all my knobs on the back (Gain, Level, etc) were changed during the move, does anyone know where I should set them please? It was about 3 years ago since I did the last calibration so I have completely forgotten everything about it so please feel free to treat me as a beginner. PS: I do have an SPL meter if that is required.