Right now I have 2 sets of polk ex357 5X7's (I know comps would be best but I dont have the money) 2 Cerwin Vega Hed 12's powered by a Visonik 1000 watt amp. and my head unit is a Kenwood mp-919. I Think In the next month Im going to get a single 12" Brahma. Am I going to notice a world of difference with the brahma. and also would It be a good idea to upgrade to a jbl 1200.