Subs move too much when the music plays and it isn't tight and firm. So this produces garbage bass, it even hurts to listen to it. not pleasant at all. What should i do to fix it ? its an audiobahn a8002t producing 800watts at 4 ohms and the 2 subs are cervin wega 12's 600 rms. the deck is a pioneer 680p i think...can't remember.... so what can i do to fix this ? i have the amps gain all the way down to avoid the over the jumpy prob. still not working..

Do you have the bass boost cranked? Subwoffer level control? Do you have a sub sonic filter on that amp? What type of music? If it's techno or something similar, I'd say it's the music.

Are the subs in phase?

ported box? possibily tuned badly? unloading, or maybye a bad amp/poor signal