1. Single 21" Subwoofer with 280mm Manget, 5" Voice Coil 2. RMS1000W Wholesale ... QRx 121s Dj Karaoke Speaker Box, Branded Bass Speaker ( Single 21 inch Subwoofer ) * Frequency Response (±3 dB): 35 Hz - 215 Hz* Sensitivity ... Ring* Net weight: 105kg * Low Frequency Driver: 1×21 inch, 280mm magnet, 5 inch voice coil* Input Connectors: Neutrik NL4MPX2 QRx 121s Dj ...