I currently have 3 12" Pioneers 150 Watts RMS with a Cadence 600 Watt RMS amp hooked up parallel into 1 ohm, I have 4 matching 6x8 Kenwood door speakers with just the Pioneer head unit but sound great. My car is a 2005 Ford Taurus. My setup sounds great to all my friends and the car next to me but isn't loud enough for me but I'm looking into upgrading. I was planning on 2 12" JL W7's then I got over the hype and fell in love with the look of Kicker's solobaric subs. Now the problem, I don't know what to go with, I'm used to 12's but am thinking about going with 2 15's.  No matter what atleast 2 subs but can't decide if I want the L5 or L7's and in 12" or 15" in the DVC 2 ohm to wire to 1 ohm and plan on getting another matching amp to the Cadence one I have which sounds GREAT unless someone can convince me otherwise. I listen to mostley rap but like alternative and country as well. Main thing that bothers me is Lil Wyte has a song with low bass test and I can't pick up the low ones like I would like. I have more questions but not til I know which subs to go with. Is there that huge of a difference in the L7's from the L5's besides $150? I really appreciate any answers and anyone who reads this all the way through sorry so long but really need advice from someone who knows more than me. Slowley learning more and more on stereos but don't know everything so just let me know your advice.
Thanks to anyone who helps.
Robert  

There's a considerable difference between the L5's and L7's.  Powerhandling, brute build design, etc....  The thing to remember is that a square subwoofer has almost the same cone surface area as the next size up round sub.  Simply put a 12" square sub moves about as much air as a 15" round sub.  The kicker's will give you the SPL you're craving, although you'd be better off matching things up, the 12L5 matching the RMS rating of your current amp, if you'd get a second amp you'd run both subs to their full potential, which is the ideal situation.  If you'd rather have the 15L5 or either L7 then I'd recommend an upgrade on the amp to keep the power up to the recommended RMS wattage of the subs, or even a litle higher, it doesn't hurt anything to have a little headroom.  Also, whichever you decide to go with I'd recommend ported enclosures for them, since you like rap music a ported enclosure will play deeper louder than a sealed.  Hope all this info helps, Have Fun!  

I would have to disagree on a few things..

No offence to anyone.. and nothing against kicker.. but I've never seen an L7 that could hold to it's RMS rating.. They almost always blow if you match RMS rating on amp and sub. I've heard nothing but complaints about them. They are a very powerful sub I will admit.

Some subs that you might not have thought of..
Rockford Fosgate P3
MTX's Square sub
Memphis Audio's M3

or (if you have the airspace.. lol) Memphis Audio's MOJO subs. I know several individuals that have gone from blowing L7's to MOJO's.. they all tell me that it hits harder.. and none of them have blown a MOJO.  

the mojo is a good sub as long as you get the right amp to power them but if u put 2 L7 15'z on a kicker zx1500.1 then they will sound great but they box also matters, but if you do try mojos get the memphis power refrence 2500 watt amp and a ported box then they will beat alot of things out there, i have the new mojos and that amp and my friends can't compete and even the local car shop doesnt have or know of anything louder the alpine head unit is also go to go with and then infinity kappas have the best sound quality on a 4 channel amp and power accoustic makes good tweeters with built in crossovers make for easy instilation!!