It is easy to solve you problem........Replace your stock battery with a Kinetik HC2000 and add 2 Kinetik HC 600's and get rid of your cap.....most caps are "crap" and do not have the power they say they have.........
If you havent heard of Kinetik, i tis the greatest thing out there for systems....all of the big SPL competitors are using them, along with manufacturers like Pioneer, Alpine, JL, Kicker, Orion/PPI/DEI, for there Demo vehicles
www.kinetikaudio.com