what you have is left and right (Stereo) but only 1 channel, now i would imagine u should either have 2 sets in wire for or 1 set in a jack form u should either get a graphic equaliser (sp) and split the audio into seperate Hz and send the high freuencys to one amp and low to another OR get one amp with a bypass and send one set of frequency's to the amp its using and the rest to another the cheapest is the set up without the eaquiliser, it is easy and quick and best bet is to get a 4 channel amp which does the lot, it has left and right in a range of frequencys and u can send low to anything u want and high to anything u want, so low to a subm high to a set of 6*9's i had an american legacy cheap thing which ran a sub and 6*9's, very cost effective let us no if u need more help