I recently installed an old subwoofer I had in the 11th gen by tapping into the rear speaker and using a Kicker LoC and NVX Remote Turn On Module (This fixes the thump that happens when it first turns on using the factory stereo). The box I had slid around and actually flipped over and scratched...
I'm having an issue with the Alpine Type-X I just installed where when I turn on the car the sub makes a thump. I checked the ground and even moved it to the floor of the trunk, and it's sanded to bare metal. I'm using the A90M amp by splicing one of the stock speakers and adding a RCA adapter...