JBL JRX218SD 18" Compact Subwoofer woofer with a cast frame and 3" voice-coil.

Features    

• 18 in. compact subwoofer.  
• 350 W (continuous), 1400 W (peak) power capacity.  
• The rugged enclosure is constructed from 19 mm (.75 in) MDF (Medium Density Fiberboard) using advanced adhesives and mechanical fastener technology for durability and improved low-frequency performance. The enclosure is covered in black carpet.  
• A top mounted, cast aluminum 36 mm pole mount receptacle can receive an optional SS3BK pole to facilitate use of the JRX218S as a base for a midhigh speaker cabinet.  
• Non-resonant, all steel handles are used.  
• Attractive 18-gauge perforated steel grille protects components from damage.

Specifications

• Power Rating    :    350 W / 1400 W   
• Frequency Range (-10 dB)    :    34 Hz - 250 Hz   
• Frequency Response (±3 dB)    :    53 Hz - 250 Hz   
• Sensitivity (@1m)    :    98 dB   
• Nominal Impedence    :    4 ohms   
• Recommended Amplifier Power    :    350 W to 700 W into 4 ohms   
• Maximum SPL    :    133 dB peak, @1 m (3.3 ft)   
• Dimensions (H x W x D)    :    605 mm x 508 mm x 551 mm  (23.8 in x 20.0 in x 21.7 in)   
• Net Weight    :    32.2 kg (71 lb)   
• Low Frequency Driver    :    M118-4   
• Input Connectors    :    Neutrik® Speakon® NL-4 (x2); parallel   
• Grille    :    18-gauge, powder-coated steel