Ok ive run all the wires from the amp to the rear of the hu. (RCA and Remote). Ive got that I splice the + of one side of the RCA to the RR and the - to the Common Ground and for the other RCA I hook + to LR and - to common Ground. Please correct me if im wrong. First of which wire is the common ground? And Which is the remote. Diagrams would help.

 

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Nobodys wired a sub amp to a stock hu?

 

Well does anyone have a wiring diagram for a 2000 Audi A4 with a concert stereo. I looked at the wiring diagram in the AF DIY but the plugs are different and I dont know what the abriviations mean on the wiring diagram on the hu.

 

you need a high to low converter to hook up an amp to an factory radio the remote wire to the amp goes to the switched igition wire on the back of the head unit they sell high to low level convertors at best buy for 20 dollars after you get one you hook up the convertor to either the front set of speakers or the rear then hook the rcas to the other side of the convertor

it looks like this
http://www.crutchfield.com/S-Wo2uwMa...11&tp=2001

 

the switched igition wire you need for the remote wire is on the harness that is plugged in to the back of the factory radio with less wires out of the 2
and on the other harness that has the most wires is the speaker side the rear speaker wire are on the top and bottom the fronts are in the middle i don't rember which way those plugs are plugged in on the factory radio they should be a black one and a brown one if you have a red one on top of the other two that is what feeds the amp that powers the rear speakers and may also feed the factory change if you have one

 

I hooked up a signal sensing 250Watt JL amp to my factory deck.

Since its a signal sensing amp, it takes ~3 seconds to turn on, but easy install & well worth it nto to have to pull apart my factory deck. I tapped into the rear speaker, got one of them fancy RCA converter things, then hooked up my amp. I have my amp hidden in the compartment for the Jack / CD Changer.. I just removed the mounting rack for the CD Changer to make some room. I ahve a custom fibrglass box with a 13.5" JL sub mounted in it off on the right hand side. Looks sexy.

Anyways, when I want bass, I just turn on my rear speakers... when I want it off, I just turn my dial so that music only comes out of my front speakers. Suites me just fine!

P.S. where did you guys run your power through the firewall? I ended up running mine through the hood-popper.. Just knocked out the rubber stop & caulked up the remaining space. Ran the power cord throught here and along the driver's side under the floor trim