If you are in search of the ultimate Woofer, this is it! JBL has leveraged all engineering resources to develop quite simply the best Subwoofer money can buy. Symmetrical Field Geometry ensures linear Cone travel and low Distortion at virtually any level by creating a uniform magnetic Field around the Coil. Die-Cast Basket. Differential Drive Design (DDD) motor Die-cast vented basket Kevlar ®-impregnated paper woofer cone Nitrile-butylene surround Power handling RMS: 600 watts Power handling Peak: 3,000 watts Cut-out diameter: 9-3/16'' Mounting depth: 9-1/8'' Sensitivity: 90dB Dual 6-ohm voice coils