I got 4 new speakers for my ampeg 4x10 cab, and like a complete idiot, didn't pay attention to the wiring when i disconnected the old speakers. the cabinet has a horn, so the red and black wires coming from the input go to the horn. there are blue and white wires that go to the speakers. the speakers are wired series-parallel, so which of the blue and white wires is positive and which is negative? also, i appear to have an extra wire that i'm not sure where it goes. if someone could help me figure out how to wire my cab, that would be excellent. thanks.