Car Stereos: speaker to amp wiring, rca cables, signal cables

Question
when wiring replacement speakers to an amp do i wire them to my headunit or directly to the amp with rcas to HU. if its directly to the amp how would i run the new wires to amp. since im amping them where should i wire the left-side speakers without getting distortion from the power wire.

Answer
Hi Jay,

If you're planning to use an amplifier with your new speakers, then they need to be connected directly to the amplifier's outputs and not to the head unit.  The amplifier will be connected to the head unit through the RCA cables.  It's important that the speakers are not connected to the head unit and the amplifier together--this will quickly damage the head unit.

The easiest way to make the connection is to just connect to the factory speaker wires behind the head unit, and extend them to the amplifier.  Be aware, though, that many vehicles include factory amplifiers.  If your car is equipped with a factory amp, you'll need to find the speaker outputs at the stock amp, not at the head unit.  

The preferred method is to just run new speaker wires from each speaker directly to the amplifier.  This is much easier in some cars than others; it might be difficult or impossible to run wires through the factory conduits into the doors of some vehicles.

Don't worry about routing speaker wires next to power wires; the higher voltage running through the speaker wires makes them less prone to interference than low-level signal cables, and the power wire isn't really as much of a noise source as many people think.

Hope this helps!

Brian