Currently I have two 15" MTX 7500s, and a Merlin Series II amp. It will cost me roughly $460 to upgrade my 7500s to the 8500s, to include a new box and upgraded amp. I am tossing the 3.0 capacitor, and replacing it with an Optima red top(I was able to aquire about 9 of them at no cost). Would this be a smart move at all? As of right now I am satisfied with my setup, but now I have the cash to make it better. I cannot afford to go to the 9500s because that will cost much more, but I will see. Any opinions?