DESC: We developed a new ribbed cone insert (patent pending) to stiffen the cone and lower the resonant frequency. The aluminum die-cast rib insert also direct-couples to the voice coil former to draw 50% of the heat away from the voice coil to the rib insert (heat sink) and strengthen the bond between voice coil former and the cone. This revolutionary rib insert allows the woofer to handle 56% more power without sacrificing sensitivity. Your competition will never know what hit them.