solved problem. the a of the a-b speakers buttons somehow disconnected. so my mains were not working and when switching channels i got that bump from the sub. pushing in the button brought my mains back and stopped the bass bump. don't know why though.
I have the Yamaha rxv-800 (to download manual: http://download.yamaha.com/search/pr...uct_id=1064064) and am using a Paradigm PD-8. We recently had a thunder/lightening storm that fried the board within our security panel, and also may have done something to either the sub or the AVR. For the...