I'm installing a new speaker system in my car, but can't get any sound from the subs. I'm using the factory head unit, and have a line converter wired into the rear speakers. The rear factory speakers work so I know there is a signal coming through. The amp has power, and both the amp and speakers have tested fine. I have put a new line converter and RCA cables on and still no response from the subs. What else could be the problem?

 

Have you verified that the amp is, in fact, on ?