Fitting An Audi Subwoofer

[ant24-7]

hello i have an audi a4 facelift model, b5, with the sandard system fitted, i have recanty bought a orig**** audi sub and power amp to fit the car,

i have read that the standard system is set up as follows standard audi head unit, the front speakers are powered off the head unit and the rear speakers are also feed off the head unit, with the rear left one having a small sub fitted to it to power the back two,

what i ideally want is to fit the audi sub and amp and that to run the full sound system if not to just power the rear speakers, to just do the rear speakers will i be able to do this off the current wiring loom that is fitted in to the car to the rear speakers?

i will be happy to just doing the rear speakers off the sub/amp if anyone has any ideas on doing this or has done some thing like it before i would love to hear from you about your experiences off this.

thank you.

[dcc236]

I've got the same car and system setup. For clarity:

- This is known as the non-Bose system. It will be using either a 2-din Symphony or a sindle-din Concert head unit.
- The stock 4" front splits are run of the head unit's internal amplifier.
- The rears are 6.5" coaxial speakers. They use line level outs from the head unit to the left rear speaker's amplifier. This amplifier then runs the two rear speakers.

The stock Audi subwoofers are not too good, so I wouldn't bother installing them. Your better off using an aftermarket 10" or 12" subwoofer in a sealed box and an appropriate amplifier. A setup like this will put the Audi subwoofers to shame.

Other than power, all the connections you need can be picked up from the left rear speaker amplifier, ie. line outs from the h/u and amp remote on/off. For power, run an appropriate guage wire (eg. 4 guage) direclty to the battery and ensure it is fused within a foot or 2 of the battery.

Good luck with your project.

[mr_a4]

A question regarding this very same setup in my A4 Avant...

I have taken out the standard Chorus single Din head unit and replaced it with a Kenwood stereo. As you mention, I gathered from the wire diagrams on the Audi stereo that the back speakers use 'line outs' rather than standard speaker outs.

With this in mind, I have connected the Kenwood directly to the front speakers and have put RCA plugs on the rear speaker line out cables, so that they plug into the 'Amp Out' connectors on the back of the new headunit.

All works okay, but the sound level coming through the back speakers is now very low. I have tried everything.

Just as a thought, I notice the 'line outs' on the old Audi stereo diagram have 'RF', 'RR', 'LF' & 'LR'. Could I use the amp to drive all the speakers? ...The Audi stereo only seemed to utilise the RF and LF channels.

Any ideas?

Thanks.

P.S. I have the Audi sub fitted too.

[dcc236]

Sounds like the amp is not powering up. I am not certain but I think all the required signals came from the stock h/u. To ensure it is working the stock amp requires the following:
- LR & RR line level
- Power & earth
- Amp remote on/off signal.

have never done it but I would expect those rear speakers can be driven by the amp in your h/u. You'd need to run speaker cable to those rear speakers (or splice into the stock line level input wires if you don't want to go to the trouble of putting in new wire) and bypass the stock amp. A bit of mucking around but I would expect it is do-able.