I have this Kenwood powered subwoofer that I would like to add to the factory entune radio on my 2017 Off Road. 6. Can the same wires I'm using for the inputs on the alpine amp be used for the subwoofer also? Mount the subwoofer level control if it is being used. Route the cable safely out of the way of moving components in your vehic le such as brake, steering, and seat mechanisms. I am attempting to connect an Alpine ktp445-U anplifier to my factory stereo using speaker level inputs on the amp. Any information would greatly be appreciated. Anyone have any legitimate experience installing powered subwoofers into existing factory car stereo? Route the end of the cable to the location you plan to mount control. A factory stereo system could have a very disappointing bass. I would also like to add a powered sub in the future and still maintain the factory radio. Proceed to the end of the subwoofer and locate the control panel. Hello I just got my 07 VW GLI Jetta with the 6 disc cd change stereo and SAT, I was wondering if theres anyway I can install my Amp to this without having to get another stereo because this stereo is pretty nice and I dont want to lose the SAT and cd changer. The solution to this is to install a subwoofer to the factory stereo. Not a lot of us are savvy techies, so we’re here to guide you through it step by step. I know on my old Subaru that they made what was called a breakout harness that allowed me to tap into the wiring harness with out splicing into anything. If you are connecting the subwoofer to an original factory stereo, connect the supplied high-level signal wiring harness to the appropriate left and right speaker wires using wire splice taps. I know what you’re thinking, just how hard is it to do this? Or would I need a 5 channel LoC for that? 5. subwoofer.