Good day for the first time ! First of all thanks, for the tips how to get the door panel off and then the boxes. I bought from Alpine a system for my Passat 3BG, Alpine SXE-1750S > Front doors 2 – Ways Speaker Kombo System 2 x 280 Watt Max / 2 x 45 Watt RMS 165mm Diameter ( Bass ) 30mm Diameter ( tweeter ) Capacitor / Elko on tweeter 60 – 20,000 Hz 90 db 4 Ohm Alpine SXE-1725S > Rear doors / Sides Rear 2 – Ways Coaxial Sys tem 2 x 220 Watt Max / 2 x 40 Watt RMS 165mm Diameter 47mm Installation depth 60 – 20,000 Hz 92 db 4 Ohm My problem now is this, I built and connected the rear boxes, they also work, but don’t have the sound I imagine. I had a 2-way combo system in it before and have now connected the 2-way coaxial system! Can someone help me further ?