The Cerwin-Vega CVP-121X is a 21" subwoofer that features enormous amounts of power handling capability in a compact design. The C VP-121X is also one of the best values on the market. This subwoofer features Cerwin-Vega's innovative Stroker technology, which utilizes a three spider driver design to optimize cone excursion and voice coil efficiency. The CVP-121X subwoofer is capable of handling massive amounts of power - 2000 watts continuous and 4000 watts peak - for overwhelming bass reproduction. To add to the CVP-121X's unique design, the subwoofer is housed in a cabinet the size of a traditional 18" subwoofer, and includes a cast aluminum grille that functions as a heat sink for the subwoofer's driver. Cerwin-Vega has incorporated design elements in their new line of passive subwoofers that allow for flexibility in the configuration. The CVP-121X subwoofer also features three pole cups that allow for the addition of up to three top boxes.