I have heard a lot of cheap subs in my life and the only thing I too say is damn. I am running a Kenwood 1800W amp on two L5's in a grand cherokee and they made my old deck ship sometimes. If I had a DB meter I could tell You just how loud they are, but trust me they shake everything.
My DVC 2ohm 12" L5 continues to impress me after 1 year of listening. It hits plenty hard and sounds great but would like to hear it hit harder on the lower frequencies. Box is approx. 0.9 cu. ft. Signal and power delivered by Alpine h.u. w/ 2 volt pre outs and a Crunch 1000.1 amp; wired @ 1 ohm.
Iv heard many kicker systems and iv got to say the L5 is a great sounding sub. the only bad thing iv heard about them is that the voice coil gets messed up quick if not amped right, which that will happen with any subwoofer.
i have one 12kicker l5 in my f150 super crew just sittin in the back seat in a ported box. i would recommend a sealed box for that lower bass. sound great, its getting powered by a jl 500/1 at about 25hz and it hits hard. it will make my factory cd player skip, with the apeaker rms being 600 and the amp rms 500 which we all know jl under rates there amps, is a good combo. it is diff getting pushed to the max. good buy