Connecting a sub to standard concert head unit...

[A3-frankie]

Can anybody help me out,

Im wanting to fit a sub in my A3 but want to keep the standard head unit, purely because it looks right and matches the rest of the interior.

It has the concert stereo with a baby sub in the boot already.

How would i best go about this? Would i have to disconnect the sub that is already there, wouldi be able to use the wires that are already there for that sub and so on.

Any help would be much appreciated,
Thanks in advance.

 

[downie]

I'd be really interested with some help in this too. I only have the chorus system in my S3 but I need some decent bass. Where can I run a power line through the bulkhead? I cant find anywhere!
Also, where do you take the switch line to turn the amp on and off from?
Finally, is it possible to use the signal already at the sub to feed into the speaker input on the amp??

Thanks Guys

 

[AndyMac]

Yes, you can unplug the existing tupperware sub and use the rear pre-outs and remote on feed that's already there. The pin-outs for the non Bose sub are shown below. However the amp inside the tupperware sub also feeds the rear speakers so by unplugging it you lose the rears. So, you either need to splice into the feed leaving the sub amp connected, or use a 4ch amp to power the new sub and the rears together. This is what I use for my stealth sub installation on the A3/S3. I generally use a Alpine V12 4ch mounted behind the rear speaker panel. This then feeds the rears on 2 channels and the stealth sub bridged across the other two.
You have to have the gain for the rears set fairly low to avoid drowning out the feeble 2 x 20w HU powering the fronts. Obviously you have no independent fader for the sub so have to rely on using the Bass control on the HU and/or the rear fader. So I set the Bass on the HU at -2 and use a very bassy CD to set the gain for the new sub. This then gives you better sound from the cabin speakers and gives you some control over the sub without pushing too much bass to the cabin speakers.
If you have the Bose system then it's easier as the cabin speakers run off a seperate amp to the sub.
You will need to run power for the new amp.
If you PM me I can send over detailed instructions on how to run power through the bulkhead (there is a spare grommet in a very accessible position near the pollen filter on passenger side underneath the wiper splash guard).

 

[A3-frankie]

Thanks for the guides u sent me andy,

Whilst thinking about it, What are peoples views on box wadding? Is it something worthwhile or an unnecesary hassle.....

Thanks.