A/ Is there one ? B/ Where is it ? C/ How does one check it works ? I was listening to a CD last night ('JX-Son of a gun',for those that may remember it /ubbthreads/images/graemlins/cool.gif) and found that all the bass was coming from the bass speaker in the dash,which was starting to distort a bit. As I faded towards the rear,the bass disappeared,hence my question. Bose set-up,by the way.