low-level output on stock system

[DouglasABaker]

Originally Posted by superior

Wow, excellent explanation of the situation (and general audio/electrical physics too). I just had a minor question as an aside. I may purchase an amp capable of 10V line-level inputs (got some Kickers in mind) to power a new subwoofer. After I have located the signal wires from the radio headunit going into the factory amplifier, what is the best way to tap them so that the signal is split to both amps? The balanced 5V seems like it would need a special wire harness or something to maintain that +/- charge separation.

Thanks in advance for the help!

I try Glad you like it since it took a little while to write up!

Balanced signals don't require any special wire or harness - it is still a 2 wire RCA, it is just that both wires carry a signal. Regular RCA's maintain separation just fine.

Anyway, to answer your question:
Some amplifiers can accept 10V inputs into their RCA jacks, others accept them into speaker terminals. Assuming the amp you are looking at accepts them into the RCA jacks, then I would simply take the speaker wires from your head unit and wire them into RCA pairs. In other words, I would take Front Left + to the tip of one RCA and Front Left - to the corresponding Ring. Do the same with FR, RL, and RR. Once you have male connectors on each speaker wire you can then get a Y cable to with 1 female end (to mate to your newly wired male end) and 2 male ends. Run those to the 2 amps.

Alternatively, simply wire up RCA's and run them directly to your 4 channel amp and then use the passthrough RCA jacks on the amp to run to a subwoofer amp.

Doug