push in the vol button to access sub w level, and fade and balance. Push and hold the Center F and the T.Corr buttons to access more crossover options, and i think they access a bass type option, you want bass type 1 if you have subs, push the Center F button to access bass and treble levels and more frequency options. The best thing to do is play around with it untill it sounds good. Hope i was of some use.