Here is the backside of the speakers. As you can see, the GX470 subwoofer that I have is single voice coil. I'm not sure if it is 8ohm or 4ohm. When I hooked up all of the speakers to the raw wires, the stock and Audiopipe subwoofers move about equally. The MBQuart subwoofer moves with noticeably more "oomph"