The 21S-SUB is a high performance subwoofer for use with the xS-Series and xA-Series loudspeakers. The cabinet houses a single long excursion 21" driver in a bass-reflex design. The large, specially shaped reflex port enables the 21S-SUB to achieve high Sound Pressure Levels from a cabinet with a small footprint.
When operated in INFRA mode, the 21S-SUB can be used to complement other d&b subwoofers by extending the frequency response of the system down to 33 Hz. The 21S-SUB can ground stacked or flown in either orientation. It can be flown individually or in a cluster of two cabinets.
The enclosure is constructed from marine plywood with an impact resistant black paint finish. The front of the loudspeaker cabinet is protected by a rigid metal grill backed by an acoustically transparent foam. The top, bottom and rear panels each incorporate a pair of M10 threaded inserts for attaching d&b rigging hardware.
System data
Frequency response (–5 dB standard) 35 Hz - 105 Hz
Frequency response (–5 dB INFRA mode) 33 Hz - 85 Hz
Max. sound pressure (1 m, free field)
with D20/30D 134 dB
with D80 135 dB
Loudspeaker data
Nominal impedance 4 ohms
Power handling capacity (RMS/peak 10 msec) 650/2600 W
Components 1 x 21" driver
Connections 1 x NL4
screw terminal block
