Xtrons rear speakers noise but no music

[griff44]

Just fitted a new Xtrons Android radio to my Audi A3 2010 S Line. Xtrons site said i might have issues with the rear speakers if i had a Bose or non-bose with a certain loom. My loom was not shown on their site so assumed it would be ok but now installed obviously not.

I have identified that my stereo is connected to the rear speakers on the loom and there is a 12v supply going out to the sub, not actually checked the sub itself to see if there is 12v there (unsure where it is) but i have a hissing sound from the rear speakers so assume there's power there?

I'm a bit lost now, i have checked through previous posts and no one has mentioned a fix - there is talk about fitting hi-lo adapters, running the RCA cables on the xtron loom to the rear speakers etc but no easy solution

Any help would be much appreciated

I have attached some pictures to show my set up

 

[griff44]

Just found the sub (behind passenger side rear panelling in boot), sub works with the original head unit fitted but when xtrons head unit is fitted there's nothing so it cant be receiving a switch live with the xtrons unit? there's a permanent live there so will keep digging..

 

[griff44]

Really odd this, just tested the wiring going into the sub with the Audi Concert and the Xtrons, i have attached some pictures - the values differ slightly but for some reason the sub works with the Audi Concert but not for the Xtrons - the white cable switch live is 10.95v with the audi and 11.60v with the xtrons but for some reason when the xtrons unit is fitted it doesnt work

 

[griff44]

Fixed it, i needed to connect the rca cables to the back of the HU - apologies if i wasted anyone's time looking into this for us.