I have a Volfenhag 12" subwoofer,At a car show I turned it up and could barely hear it,then at volume 20 my batery cut off(peice of shi*)Then of course some guy pulled up with 2 15" rockford fosgate subs and shook da whole dagum ground.Is there some way I could make my subs louder(besides new battery)Like get a capacitor or crossover?Or is my volfenhag just a peice of shi*.