Will two 12" Audioque Hdc copper coil subs give me more spl/bass than my single 15" Alpine Type R?? HELP!?

Want to know before i go n spend $500to$600 on a pair of 12"s. And forgot to mention im NOT concerned with SQ at all am more concerned with SPL or strictly harder slammin straight low BASS! My 15" is ran on a Kenwood Excelon 1200m monoblock amp n final impedance is 4ohms (800watts rms) but its just not enough for me anymore, so instead i want to get a pair of 12"s and wire them so i have a final impedance load of 2ohms this way i will get 1,200 watts rms instead, so if not the Audioques what two 12"s can i get that will give me more bass/SPL than my current setup?? People have suggested the following (please help me narrow it down a little)... Kicker Solobarics, Memphis C3's, Sundown, DC Underground Labs, Soundstream, Orion HCCA's, Polk Audio, Diamond, etc... PLEASE HELP! looking to be heard from far away,compltly rattle my whole car (more than it already does), feel that feeling in nose,chest,throat! Dont care if its totaly SQ/sound quality material subs i mean dont want it sloppy but not looking for JL's or any subs in the SQ category just want max BASS/SPL frim two 12"s instead of my current single 15" Alpine Type R if thats not pissible to do and my 15" will be louder than two 12"s then please tell me before i go n waste 5to600dollars!! (thats my budget i have to work with. Thanx soooooo much in advance to whoever takes their time to research this n help me out! :)