JL Audio subwoofers are some the best in the industry.  JL subs are unique in the fact that they are the only car audio manufacturer to make 13" subwoofers.  Why buy 13 inch subwoofers you ask?  When you could buy a 12 inch subwoofer? or a 15 inch?  With a 13" subwoofer you get almost twice the output of a 12, but retain sound quality that will outmatch any 15 inch subwoofer.  With four series of subwoofers including the W1v2, W3v3, W6v2 and the mighty W7 series there is a subwoofer to match your car audio system.  With patents on almost every series of subwoofer, you know JL will provide the highest quality subwoofer in the car audio industry.