I have a 2000 Discovery II with the Harmon Kardon system. I have removed the two rear "subs" which here 6.5" each and 4ohm each. They were factory wired in parallel so the amp sees a 2 ohm load. I have purchased an 8" Polk sub (model DXI108) in a sealed enclosure. From the HK amp there are 4 wires terminating into a plug (2+ and 2-) The plug went into the factory housing for the two subs. Since the amp saw the original setup as 2ohm I am assuming that I can use a single 2ohm speaker and all is well. My question is this: Do I use both + wires and both - wires with the single speaker or just one set? Also The original two subs were dual voice coil and the Polk is a single voice coil will this make a difference in how I need to wire?