The bass reflex design LS1004B 2 x 18" Elite Series Passive Subwoofer from Yorkville Sound features two 18" subwoofers handling 2,800W program each, and is suitable for touring or fixed installations. The cabinet is constructed of 15mm 11-ply Baltic Birch with heavy internal bracing for reduced resonance and durability. All enclosures are covered in a black carpet covering and incorporate metal corner protectors, and a finish of black ultrathane paint. The subwoofer has two rugged curved anti-resonant metal grilles, and 1/4" or Speakon input connectors. Additionally, the Speakon connectors feature a configuration switch which allows instant reversal of Speakon jack pinouts for easy single wire hook-up using optional four wire Speakon cables.