PIONEER TS-WX306B/XIID (BOX)Comes installed in a uniquely shaped bass reflex box, these sub woofers are an excellent alternative for tube sub woofer by Pioneer, providing the same brilliant experience with 1300 W (max) power. Features Voice Coil Cooling System Heat radiation is the key point to improve durability and sound. Aluminum Cap & Aluminum Bobbin allow heat to be removed from the center of the subwoofer for improved frequency response and high power handling. A: Heat is