Aftermarket headunit and OE sub

[Az]

Hi guys,

The previous owner fitted an aftermarket headunit to my S3 and it's only wired to the 4 speakers but not the sub, without the sub it sounds tinny and nasty but I know if the sub was working it would make the world of difference.

An old A3 of mine had an aftermarket headunit fittedby the previous owner but that was somehow wired into the sub as well and sounded great!

Is there a specific iso harness that you can buy that utilises the OE sub which is a simple plug and play? Or is it more complicated than that?

Thanks in advance,
Az

 

[Az]

Oh forgot to mention it's a pre-facelift with a non Bose system.

 

[AndyMac]

No it's easy, you just need a PC9-404 adapter. Connect this to the sub pre-out on the HU (if it has one) and connect the blue flying lead to the "remote on" lead on the HU. This will turn on the sub/rear amp and feed the subwoofer pre-out to it. If the HU doesn't have a sub pre-out then you'll have to use the rear RCA's. The previous owner must have wired the rears directly to the HU, which is good, but you will find the sub will be totally overpowered by the cabin speakers. The stock system only has 4 x 20w to the cabin speakers and the sub is 1 x 50w. With an aftermarket HU kicking out 4 x 50w+ you will struggle to hear the feeble tupperware box.

 

[Az]

Excellent post Andy! Thanks a lot, that's helped me out a lot!

 

[Az]

By the way Andy, was it you that used to make your own sub box with a JL audio sub in it for the 8L's? If so do you still do them?

 

[AndyMac]

Yes still doing them