APPLICATIONS
The SW2421CFA multi-pattern native gradient subwoofer is engineered for applications where maximum acoustic output, extended low-frequency response and controlled directivity are required within a compact footprint. Designed as a high power-density low-frequency system, the SW2421CFA delivers exceptionally high SPL while maintaining accuracy and definition in demanding live sound environments.
The internally generated pressure-gradient configuration allows the SW2421CFA to operate in Cardioid, Hypercardioid or End Fire modes through DSP presets, eliminating the need for reversing cabinets or building complex subwoofer arrays. This approach is particularly valuable where rear rejection, stage control and low-frequency precision are critical.
Optimized for both ground-stacked and flown deployment, the SW2421CFA integrates seamlessly with AX2022A and AX2022P line arrays through compatible rigging hardware, enabling predictable acoustic behavior and unified deployment across the full frequency range.
DESCRIPTION
The SW2421CFA represents an advanced approach to low-frequency power density and directional control. The design combines a front-loaded 24" high-excursion neodymium transducer with a rear-mounted 21" neodymium transducer inside a single enclosure.
The 24" driver operates as the primary low-frequency radiator optimized for maximum displacement and acoustic output, while the 21" transducer functions as an active rear element. Through precise DSP management of amplitude, phase and delay relationships, the system generates directional radiation patterns fully controlled by presets.
Unlike traditional cardioid subwoofer systems requiring multiple cabinets or reversed configurations, the SW2421CFA achieves directional control entirely within a single enclosure. This simplifies deployment, improves consistency and enables rapid mode switching without physical reconfiguration.
TRANSDUCERS
The SW2421CFA employs complementary high-excursion neodymium transducers consisting of a front-loaded 24" driver with 6" voice coil and a rear-mounted 21" driver with 4.5" voice coil operating as an active rear element in the pressure-gradient system.
Three selectable operating modes are available through DSP presets:
• Cardioid for maximum rear rejection and stage control
• Hypercardioid for narrower forward coverage with stronger directional focus
• End Fire for maximum forward summation and output
This multi-pattern pressure-gradient architecture achieves controlled directivity within a single cabinet while eliminating the complexity and space requirements of conventional cardioid subwoofer arrays.
SYSTEM CONCEPT AND SONIC PERFORMANCE
Constructed from reinforced 18 mm phenolic birch plywood with high-resistance water-based coating, the SW2421CFA is designed to withstand both touring and permanent installation environments. The internal acoustic loading supports extremely high acoustic pressure levels while preserving fast transient response and low distortion across the operating bandwidth.
The system provides extended low-frequency response from 31 Hz to 90 Hz with controlled radiation and improved efficiency. Cardioid mode minimizes unwanted low-frequency energy on stage, while End Fire mode maximizes forward impact and audience coverage.
SIGNAL PROCESSING AND POWER AMPLIFIERS
The SW2421CFA integrates two dedicated 4000 W Class-D amplifier modules with SMPS and PFC, providing 8000 W total system power. Independent fifth-generation SHARC+ floating-point DSP channels operating at 32-bit resolution with 24-bit converters deliver 121 dB dynamic range per channel and precise control of the pressure-gradient behavior.
Network connectivity is based on dual redundant gigabit Ethernet ports supporting AVB-Milan audio transport at 96/48 kHz together with AES70 standardized control and device management. The AXIOM AUDIA software platform enables unified remote control, monitoring and configuration alongside other AXIOM active loudspeakers and Q-NEX+ amplified systems within the same workspace.
| SYSTEM | |
| System’s Acoustic Principle | Native Active Cardioid Subwoofer |
| Frequency Response (-3dB) | 31 Hz – 90Hz (Processed) |
| Horizontal Coverage (-6dB) | Cardioid / Hypercardioid / Endfire (preset dependant) |
| Vertical Coverage (-6dB) | Cardioid / Hypercardioid / Endfire (preset dependant) |
| Maximum Peak SPL | 146 dBSPL (AES 75 Standard) @1m |
| TRANSDUCERS | |
| Front | 24”(610mm) Diaphragm - 6” (152mm) Voice coil, Neodymium Subwoofer, 4Ω |
| Back | 21”(260mm) Diaphragm - 4,5” (115mm) Tetracoil, Neodymium Subwoofer, 4Ω |
| ELECTRICAL | |
| Input Impedance | 30 kΩ balanced, 15 kΩ unbalanced |
| Input Sensitivity | +4dBu / 1.25 V |
| Audio Networking | AVB - Milan |
| Signal Processing | Fifth-generation SHARC+ 32-bit floating-point DSP |
| Direct access Controls | 3 Presets (End Fire / Hyper / Cardioid) |
| Remote Control | AUDIA software with AES70 device control standard |
| Amplifier Type | Class D with SMPS and PFC |
| Output Power | 4000 W + 4000 W |
| Mains Voltage Range (Vac) | 100 - 240 V~ ±10% 50/60 Hz |
| IN / OUT Connectors | Neutrik XLR-M / XLR-F |
| IN / OUT Network Connectors | ETHERCON® (NE8FAV) |
| Mains Connector | PowerCon TRUE1 (NAC3PX In/Out) |
| Cooling | Variable speed DC fan |
| ENCLOSURE & CONSTRUCTION | |
| Dimensions (W x H x D) | 830 mm (W) x 1013 mm (H) x 800 mm (D) |
| Enclosure Material | 18mm, reinforced Phenolic Birch |
| Paint | High resistance, water based paint |
| Flying System | External Frame suspension system, back hinge |
| Net Weight | 165kg Kg (363.7 lbs.) |
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