Description

Installation Specific High Performance Subwoofer with Compact Footprint

The 21S-SUB is a high performance subwoofer for use with the xS-Series and xA-Series loudspeakers and is intended for a wide range of permanently installed applications. 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 33Hz. The 21S-SUB can be 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. The Weather Resistant (WR) option provides an IP55 rating that enables the operation of loudspeakers in changing ambient conditions, and features a fixed cable.

Amplifiers
The d&b 30D amplifier is recommended to drive the 21S-SUB. The d&b D20 and D80 can also be used.

System data 

• Frequency response (–5 dB standard): 35 – 105 Hz
• Frequency response (–5 dB INFRA mode): 33 – 85 Hz
• Max. sound pressure (1m, free field) [1]
  with D20/30D: 134dB
  with D80: 134dB
• Cabinets per amplifier channel: 1

Loudspeaker data

• Configuration: Installation specific high performance subwoofer with compact footprint
• Nominal impedance: 4 Ω
• Power handling capacity (RMS/peak 10 ms): 650/2600 W
• Components: 21″ driver with neodymium magnet
• Connections:
  1 x NL4
  1 x screw terminal block

Dimensions, weight

• Dimensions (H x W x D): 1100 x 580 x 526 mm (43.3 x 22.8 x 20.7″)
• Weight: 54 kg (119 lb)

[1] SPL max peak test signal: pink noise with crest factor 4

Application information is presented for guidance only. d&b reserves the right to make any necessary changes to the products and the published specifications. As part of the ongoing development program d&b tries to maintain the highest degree of product compatibility.