For about a year and a half now I have been using a Rockford Fosgate power 1050s to run my 15" XXX. Up until a week ago it was working great, then one day it just seemed to be a bit quieter than normal. After testing the voltage coming off both channels, I found that one of the channels was not responding to my bass boost knob, while the other was working just fine. Does anyone know what might be wrong with it?