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 option enables the operation of loudspeakers in changing ambient conditions, and features a fixed cable. The 21S-SUB can also be supplied in any RAL colour. This Special Colour option can be provided for rigging accessories.
The d&b audiotechnik loudspeaker range is designed exclusively for operation with d&b amplifiers. These provide power as well as comprehensive control and protection functions tailored to achieve the performance, reliability and longevity associated with the d&b System approach. The d&b 30D amplifier is recommended to drive the 21S-SUB. The d&b D20 and D80 amplifiers can also be used with the appropriate loudspeaker configuration selected.
|Frequency response (–5 dB standard)||35 - 105 Hz|
|Frequency response (–5 dB INFRA mode)||33 - 85 Hz|
Max. sound pressure (1m, free field)1
|Cabinets per amplifier channel||1|
|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|
1 x NL4
1 x screw terminal block
|Dimensions (H x W x D)||
1100 x 580 x 526 mm
43.3 x 22.8 x 20.7"
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.
The loudspeaker shall consist of a single 21" long excursion low frequency neodymium driver in bass-reflex design.
The loudspeaker shall only be operated by a dedicated, compatible controller amplifier.
The cabinet enclosure shall be made from marine plywood with an impact resistant black paint finish.
Special colours according to RAL table and a weather resistant option shall be available upon request.
The drivers shall be protected by a rigid metal grill backed by an acoustically transparent foam.
Four rubber feet shall be incorporated in the bottom panel to prevent the cabinet from movement and four corresponding recesses in the top panel shall be incorporated to prevent movement of stacked cabinets.
The cabinet shall incorporate two M10 threaded inserts on the top, bottom and side panels for the secure attachment of dedicated mounting brackets.
The connection panel on the back shall be recessed and fitted with one speakon NL4 M socket and a two pole screw terminal block. A cover plate for protection of the connection panel shall be included.
The power handling capacity shall be 650 W RMS and 2600 W peak (10 ms). The frequency response (–5 dB) measured on axis shall be 35 Hz to 105 Hz with a maximum sound pressure of at least 135 dB.
The dimensions (WxHxD) shall not exceed 580 x 1100 x 526 mm (22.8" x 43.3" x 20.7") and shall weigh no more than 54 kg (119 lb).
The loudspeaker shall be the 21S-SUB by d&b audiotechnik GmbH.