Can I add a 12" Kicker L5 to my Kenwood excelon x1200 amp and single 15" alpine type R for more bass/spl?

Nees more bass want my system to hit harder and have the chance to get a realy good deal on the kicker solo.. Currently have a dual 2ohm single 15" alpine type r running at 4ohms in a pirted box getting roughly 800watts rms.. Trued wiring the sub to a 1ohm load but the kenwood cant handle it even thou they claim its 1ohm stable so im figuring the best I can do with it is a 2ohm load so il have to make sure the kicker is also a dual 2ohm to get a funal 2ohm impedance.. So im wondering will this give ne more bass or will it just take away power from my 15" and leave me with the same amount of bass/spl or less than I already have? Thanx so much to whiever can help me figure this out.