So, I have a 2005 Audi A4 B7 and I have replaced my OEM HU (Concert 2 1DIN) -- factory amp, subwoofer , non-BOSE --- with an AM one (Kenwood) and I have got 3 issues: 1. The HU doesn't turn on indepedently or turn off after I remove the key (I tried wiring it to a fuse -- but that meant the HU would only turn on on 'ON" position) - I gave up and now I manually turn it on / off by pressing the button on the HU. 2. Rear speakers and the subwoofer are quieter than the front ones -- I have got *adapter number 1* -- Should I buy one of *adapter number 2* Maybe the RCAs would help ? Or a HIGH - LOW converter ? Like *HIGH-LOW CONVERTER* ---- I have also found another adapter which has a little black box - is it a high-low converter by any chance ? I'm talking about *adapter number 3* 3. In order to turn on the AM HU, I had to wire the red and yellow wires together (wires coming out of the black connector -- see my adapter) //I couldn't post url=/// so I chose to upload photos. A1 - Adapter number 1 and so on. I know this has been asked before, but I couldn't find a final answer on Google.