I have 2 15"s running through a 2000 Watt DHD amp, and my left input channel on my amp doesnt work sometimes. It works when it wants too, then it stops, then it starts working again. But if you take out the left ch rca plug and stick it back in, it will play also. My right channel works, so i have both 15"s running off one channel. Its not the RCA Plugs because i bought brand new Ones and it still does the same thing. What could it be? Any help would be appreciated.