15" Die-Cast Dual Voice Coil Subwoofer engineered to put you in the front row at your next concert. They deliver deep solid, tight Bass that can only be delivered by JBL, the leader in concert Sound. JBL GTO subwoofers include die-cast aluminum baskets, polypropylene cones, rubber surrounds and a unique tinsel wire protector that also strengthens joint between the cone, the voice coil and the spider. That joint is the most critical of all and must withstand more stress than any other point in the moving assembly. Great performance and superior reliability have been JBL’s hallmark for over 60 years and the new JBL GTO subwoofers offer both at affordable prices. The JBL Grand Touring Die-Cast Subwoofers are designed to be used in sealed, vented and bandpass enclosures.