tylersmith737

Hey guys,

I have a few questions for people who know about upgrading the stock Concert audio system.

I am on a budget, so lets not get too excited with crazy upgrades , but I do have a bit of tolerance for spending . Here is what I thought I would do... for now

SINCE there is front line-out channels left open on the head unit, because the rears are wired & powered by the mini 2X20 amp in the back, I wanna wire those front channels to my 250W amp to power my 10'' sub to be mounted in the trunk. That seems to be the easy part ( hopefully ).. please let me know if this is NOT a good thing, or if there is a certain way to do it.

The real decision is this. I don't plan on hooking up any speakers to the amp, just the sub. I am okaywith the rear deck lid speakers for now, but the fronts MUST GO. I was looking at 3.5'' ( I know stock's are 4''.. but with these I don't need adapters, and they will work just fine.. maybe ) Infinity Reference speakers that have the deep drivers, BUT here is the possible problem . They are 2OHM speakers. The big question is, can I use 2ohm speakers with the stock head unit, or will it get fried? I can find 4ohm ones no problem, just the infinity's have good bass response, and they would not need more power than they would get from the stock unit to make them work to their potential. Please let me know of any potential problems, and if you're inclined to do so, share what you have done, or are planning to do in your A4 ! I'd love to get some insight !

Comment as much as you need to, I don't wanna make any mistakes with this setup.

Cybersombosis

As far as adding a sub, I couldn't handle not having one after picking up my A4 at the end of 2009. After much research and looking through the tech article found here https://www.audiworld.com/tech/elec.html, there is an easy way to get line-out to your sub amp and it's right at the driver's side rear speaker. This is taken from the tech article which I have added and taken out less important info.

First things first. This worked for me but do this at your own risk. I will not be held responsible if you screw something up. If you don't understand something, then ask before you start snipping wires. This installation does not require you to cut any of your car's wiring so please don't. Tapping means stripping a section of insulation off of the wiring leaving the bare copper wire showing at which point you can solder another wire to it and wrap your work with electrician's tape.

These wire colors worked for me but you may want to verify that they are the same before starting by looking at the back of your wiring harness off the stereo. My OEM stereo had a diagram stuck to it with the wiring diagram.

The rear amp is a smallish thing, normally attached to the rear left speaker in the rear deck plate. There is a connector plugged into the side of the speaker when you drop your drivers side rear seat down.

The brackets represent the slots that slid into the male harness end. The side with the outward piece is the piece I chose as the "top".

________[ ]________
(1) (2)
(3)
(4) (5)
(6)
(7) (8)
________[ ]________

1: White- Switch
2: Red-Blue lead to Right speaker
3: Brown-Red lead Right speaker
4: Red-Blue (thicker): 12v
5: Blue-Green Right pre-amp from head unit.
6: Red-Green Left pre-amp from head unit
7: Brown (thicker) Ground
8: 2 Brown-black Grounds for pre-amp leads.

In order to get line out, you just tap into the pre existing wiring using Scotch locks or stripping the wiring insulation and soldering the connection. These instructions will assume you are soldering the connections.

1. Take a set of RCA cables and cut one set of ends off making sure there is enough length to reach the amp.

2. Strip the end exposing about an inch of both the inner core and ground (outer metal sheathing). Do this for both ends then twist the grounds together from the left and right channel.

3. Strip the insulation off of the Blue/Green, Red/Green, and 1 of the Brown/Black wiring from the connector leading to the rear speaker using a razor knife. Do not cut the wires.

4. While you're under there, go ahead and strip the white wire on the connector for the amp's remote turn on.

5. Get a length of small gauge wire for your remote turn on and strip one end.

6. Get your connections ready for soldering by twisting the right RCA's inner core to the Blue/Green wire's stripped section. Then twist the left RCA's inner core to the Red/Green. Then the RCA's twisted ground from the left and right channel to Brown/Black. Finally twist the remote wire to the white wire.

7. Solder and tape up your work.

In order to get power to the amp, I ran a heavy gauge wire from the battery to the trunk. I ran ground to one of the bolts underneath the rear seat.

If you have any questions fire away. Good luck.

Doug

tylersmith737

Thanks Doug !

This seems like a great solution , and I am hoping to have time by the end of this week coming up to try this out, carefully that is. I will let you know how it goes, i'm sure everything will be fine. The instructions are worded just fine, and as far as my expertise goes, this does the trick. Next is the front door speakers !