S 21a



S 21a is a compact, high-performance self-powered touring subwoofer, designed to complement our FR-X, ARES 8 and ARES 12 series in sound reinforcement applications scaling to full stadium shows.
S 21a houses a long excursion 21″ neodymium driver and combines front diffusion, bass reflex, and transmission line design for maximum efficiency and outstanding SPL.
Rental companies favor S 21a as an alternative to industry-standard 2×18” subs, saving half the truck space and around 40% of the weight. The subwoofer can be deployed standalone, stacked or flown, making it a versatile, high-earning hire stock staple.
S 21a features an advanced AUDIOFOCUS Class D amplifier module with integral DSP and dedicated presets. Presets include omni, cardio (Front-Back) and end fire variants.
S 21a is built with pride in Belgium and coated in tough, weather-resistant polyurea to safeguard your investment. The cabinet front is protected by a rigid metal grill, backed by acoustically transparent foam.
Acoustical & Electrical Specifications
- TransducersLF : 1 x 21″
- Frequency Response28Hz-100Hz
- SPL peak / 1m (measured)139 dB
Connections & Physical Specifications
- RiggingPole socket
- Audio ConnectorsIN/LINK: 1×3-point XLR
- Power ConnectorsIN/LINK: 1×3-point powerCON
- Network Connectors2 x etherCON for control and optional Dante / AVB
- CabinetHigh grade birch plywood
- FinishHighly resistant polyurea coating
- Dimensions (H x W x D)590 x 750 x 655 mm
- Weight60kg