Issues With Newly Installed Aftermarket Head Unit


Registered User

This is my first post and i hope someone can help me, i have installed a new Alpine head unit today in my A3, i cant get any sound out of the rear speakers, do i need a special adapter? Anyone had the same issues, its replaced the standard (Audi Concert single DIN unit) my car is A3 sport on a 53 plate if that makes any difference.



Active Member
Yes you need an adapter in order to take the rear RCA's from the Alpine and feed the puny Audi rear/sub amp. You need something like this:

Large Halfords sell them, but check the unused connector on the Audi loom first as Audi did change the plug on later models.
You'll find the balance between front and rear is then shot as the Alpine will be kicking out 45-60w to the fronts where the Audi rear amp is only 25w. Better to rewire the rears directly to the HU TBH and bypass the amp, then use the adapter above just for the sub fed by the Alpines sub pre-out.


Registered User
here's my thread on the same prob:

i bought the one with a black box and its ok...but its better to re-wire your back wires stright through....Save £30 and better quality but i hate snipping wires

The blak box had an earth and a remote wire to activate the standard amp.

Its up to you but mine seems to be working ok....but you neeed a really good earth.