Audio Systems: land rover discovery 2 2003, land rover discovery 2, land rover discovery

Question
I installed a flip out pioneer head unit and two type r 12" subs. I get a constant almost sounds like interference coming from the regular speakers that is drowned out whenever i turn the volume up enough. What could cause that and what could i do to fix it?

Answer
It could be interference.  Shut the engine off and if you do not get the interference type sound then it is a function of the ignition getting into the system. It will need either filters OR there may be a bad ground or a missing ground, so check the wiring carefully.

If the noise remains even when the engine is off it is most likely a loose or mission ground somewhere in the system.

Is it heard in ALL the installed speakers?  Do you have an external amp or are they driven by the new head unit?  If there is an external amp driving those speakers, check it for proper grounding and make sure the 12v lines are coming from the right places: One should come directly from the battery - through a fuse - and the other from the head unit which is the on/off lead.

Maybe this will help, but come back to me if you get stumped.
C