Car Stereos: static noise, internal amplifier, external amplifier

Question
Hello Brian,

I have recently installed 2 6x9s (Alpine) into my parcel shelf but I am having some problems...

Before installing the front two speakers worked normally (standard). Today, once the 6x9s were in place there was a static type noise coming through all for speakers. So i disconnected the 6x9s but to my surprise the static noise was still present through the front pair. At a low volume the noise is not present...

Please can you help?

Thanks,

Allan

Answer
Hi Allan,

Unfortunately, I don't have any likely suggestions for a quick fix here.  From your description, it sounds like the head unit's internal amplifier has been overloaded. (I'm assuming your speakers are connected to a head unit, rather than an external amplifier).  You might want to check the rear speaker wires, and make sure you don't have a wire that's shorted against a metal surface in the vehicle, or positive and negative wires touching.  A short circuit is one thing that could cause this problem, and if it's occurring on the speaker wires, it wouldn't be affected by removing the rear speakers again.

If I were troubleshooting this one, I'd probably pull the head unit, and test the speaker wires with a multimeter looking for a grounded or shorted wire.  If one isn't found, however, then it's likely that the head unit's amplifier needs repair.

Good luck!

Brian