2 Amps, 9 speakers, 1 car, and very little know-how :)

[1wheel_drive]

Hi everyone!

I'm new to the forum, so let me apologize in advance for any newbie mistakes or inadvertent blunders.

I've been working to put my sound system together, and I can definitely use some help from those who are more competent than I am (probably most of you!)

A bit of background:
I bought my 2008 Audi TT coupe secondhand. The original owner was in the army and had purchased the car in Germany. He then brought it to the US, drove it, and traded it to an Audi dealership.

During the CPO process, the dealership removed most of the aftermarket stereo stuff and kindly put in a large cardboard box. They then installed the original Audi head unit. The speakers were left in place, but several of them were never connected. The amps were removed, as was the aftermarket head unit.

My goal:
I'm now looking to reinstall the 2 amps (details lower), reconnect all the speakers and replace the factory head unit with an Audi RNS-E Nav unit (details below).

My gear:

Head Unit:

I'm using an Audi TT RNS-E upgraded unit (part 8J0 035 193 F). It's much better than the standard Symphony/Concert system that TTs come with and it integrates perfectly into the console. I know there are better head units out there, but I'd like to try and work with the head unit I have.

Amps:

I have 2 identical 4-channel amps. I disassembled them, had the housings blasted and ceramic coated, and then assembled them back.

They are made by u-Dimension. It's an uncommon brand in the US, as far as I can tell, but since the car was purchased in Germany, that's what the first owner had put in. I looks like decent stuff. Please correct me if I'm wrong.

Speakers:

The car has 9 speakers total. They are also made by u-Dimension and seem to be solid.

A bass and a mid in each of the front doors - 4
A tweeter on either side of the dash - 2
A center speaker on the dash - 1
Rear speakers behind driver and passenger - 2

I'm not sure whether the rear speakers are mids or bass, as I haven't removed the panel to check yet.

Wiring:

There are wires running to all of the door speakers, but the speakers don't work. I'm thinking it's because of the way the wires were cut at the harness, when the aftermarket stereo was removed and replaced by the factory one.

The other speakers work fine.

My battery is in the trunk and I'll be mounting the amps on the back of the rear seats in the trunk area (so pretty close to power).

Questions:

Now for the fun stuff!

1) The RNS-E head-unit does not have RCA outputs but it does have pin-outs for 4 channels (FR, FL, RR, RL). There seems to be a way to get signal from them, by creating a PIN-to-RCA harness (as described here). But the question remains, which set of outputs should go to which amp?

2) The second question is which amp to use for which speakers. Originally, one of the amps had stickers for Subs and Rears. The other didn't have stickers, but I'm guessing it was for mids and tweeters. I need to know which amp to use for which speakers.

3) How do I go about getting the signal for the center channel. The head-unit doesn't have a specific output for that. Should I get it by bridging the mids?

4) Do the amps need to be connected between each other? If so...how?

5) Do you think I should use the existing wires for the speakers or try to run new ones? I'd like to avoid running new wires, especially if the car was already wired before. That being said, I have several of the panels off, the carpet is halfway up and I'll need to run a remote-on wire and a few others anyway.

I'll probably have more questions, but these are the main ones that I'm grappling with now.

Thanks so much in advance for any advice you can throw my way.

Cheers

Click to read more...

 

[Kickstand Premium Member]

Have you actually tried to put the new HU in?
A lot of factory HU are codded to the VIN and require the dealer to flash them
Even then they don't always work.
That car should have the Bose system in it which means there is a factory amplifier somewhere.
I'm guessing that's where they spliced into the wires to run from the aftermarket amps for the front speakers.
If they left you the aftermarket HU and the wiring for it I suggest using it.
Are there RCA cables running to the back ?

 

[1wheel_drive]

Thanks for replying!

I don't have the aftermarket head unit but the Audi RNS-E is a plug and play replacement for the stock one. It syncs with the car perfectly, with some minor programming in VCDS/Vagcomm. It also comes with an unlock code, so I'm not very concerned about it not working.

I'm not sure whether my particular model had Bose or not but there is a small amp in the trunk area. I'll check to see which wires run to it.

There are no other cables in the back. No RCAs, no power leads. Nothing.

 

[Kickstand Premium Member]

Well if your going to use the stick head unit then you will need a line out converter or better yet a digital sound processor.
I’m guessing the speakers behind the seats are the subs but without being there and seeing the car it’s hard to give you any advice on how to tackle it.
Having to make heads or tales of someone else’s wiring mess is enough to make you go nuts.
Your probably better off just to run new wires and start over again. Pull the door panels off and see if the speakers are hooked up.
If they are then tapping into the wires at the amp isn’t going to work but you could tap into them at the inside the car part of the miles that runs into the doors. It’s better than having to run though the door .
If they are not then reconnect them and just tap into the speaker wires that are in the trunk at the amp.
The 12volt.com should have a wire diagram

 

[1wheel_drive]

Thank for the suggestions. This is what I've been able to figure out:

It looks like the previous installers ran RCAs from the aftermarket head unit to the amps but then tapped into the factory speaker wires coming from the factory amp in the trunk.

There are wires coming out of the factory amp that have been cut and they match up to the various speaker locations.






I'm going to run RCAs and a remote turn on wire to the new head unit, which has line-outs.
And I'll probably run new speaker wire while I'm at it. But I'm still not sure how to best utilize the 2 amps.

See, in the front I have:

- TWEETER on each side of the dash
- MID in each door
- BASS in each door

And in the back, I have:

- TWEETER in each rear panel
- MID in each rear panel
- BASS on rear right

So what should the inputs and outputs be on the amps? And what should the crossovers be set to? I'm trying to avoid having passive crossover but I still can't figure out a way to get 11 separate channels (2 front tweeters, 2 front mids, 2 front bass, 2 rear tweeters, 2 rear mids, 1 rear bass) from the 8 total channels in my amps.





Thanks in advance!