My processor (Anthem AVM 20) has a "bass peak level" feature which allows the user to set the maximum output level of the sub. To set it up, a test tone is run through the subwoofer and the user adjusts the level until distortion is heard. Once this level is reached, you back the levels off a notch, and therby set the maximum output level of the sub. My problem is that I seem to be getting distortion at a very low level--around -47 db. The lowest setting is -50 db. Consequently, I am not sure if what I am hearing is actually considered distortion. The sound is akin to paper rattling--and I am wondering if this is "distortion" as such. I have a Mirage bps400 subwoofer which should be able to handle a fairly large input. Am I being too cautions setting this level?