Dual 18-inch sub with 1,200 watt continuous, 4,800 watts peak power handling. Easily delivers 133 dB SPL 1 w/1 m (139 dB peaks 1 w/1 m) at full power Two concert-proven EVX180B woofers with 4-inch voice coils have incredible fatigue resistance and excellent long-term reliability. Usable response extends to 31 Hz. Enclosure is built of 13-ply, void-free, grain-oriented Birch plywood finished in Futura, a sprayed-on polyurethane finish that is very rugged. Available in black or white. Standard versions of the QRx218S are equipped with rear-mounted pocket wheels and handles to allow one person to comfortably move the enclosure. The standard versions also have a metal stand socket and are shipped with a 34-inch steel pole for elevating satellite speakers. The QRx218S is available with L-track rigging as a special order option. The rigging versions have L-track on the top and bottom plus a single-stud pull-up point on the back. The rigging versions do not come with wheels or a stand mount.