I have a massive audio N4 amp and wasn't sure which I should get between the lvl 4 and the xl. I know that the xl peak wattage of two subs is greater than my amps but I wasn't sure if that really mattered. I want two 15's of either one. Which one should I go with? and yes I am upgrading the electrical I have a 250 amp alt and a KHC2000.