all audiobahn subs with duel voice coils have 8 terminals...it's so you can use multiple subs and not have to twist the wires together and make it look all ghetto.
If you look real close, half of the blue plastic on each side is labled + and the other half is labled -. For a 2ohm impedence (1 ohm with two subs), wire positive to positve and negative to negative, then negative on the sub to negative on the amp and positive on the sub to postive on the amp....pretty simple, eh? Now for an 8 (16 ohm with two subs) ohm load, you just wire the negatives to the postives on the sub, then positive and negative to their respective spots on the amp.