Product Overview
The DVA S1521N is a powered 21" subwoofer housed in a bass reflex enclosure that we tuned for accurate, ultra low-frequency response. It readily integrates into large DVA and DVX Series PA systems as a sub-bass unit or as a stacked subwoofer. Made of durable birch multiplex covered in robust black textured lacquer, the high-quality housing provides six carrying handles, an M20 pole mount, and bushings on the rear panel that accept casters. Pick-points for attaching DRK-10 and DRK-20 harnesses are built into the top panel to enable easy, safe stacking.
Product Features
Variable crossover frequencies
Precise limiter functions
On board delay for perfect time alignment
Preset for configuring cardiod systems
Settings accessible via rotary encoder
X-over out
RDNet network port
Product Specifications
Acoustical data 
Frequency Response [+/- 3dB]: 30 - 110 Hz
Max SPL: 139 dB
Directivity: Omnidirectional, Cardiod Option with DSP setup
LF: 21 "
Type LF: RCF Neodymium
Voice Coil LF: 4.5 "
Amplifier 
Amp Technology: Digipro
Amp Class: Class D
Power Supply: 1.5 kW SMPS
LF Amp: 1500 W/RMS
Cooling: Convection
Processor 
Controller: DSP 56 bit
AD/DA Converter: 24bit/ 96 kHz
System Presets: X-Over Delay
Phase: 0, 180 °
Limiter: RMS, Peak, Thermal
Delay Option: 0-4.5 ms internal
Crossover Frequency: LF-MF DSP, steps of 5 Hz
Slope LF-MF: 24 dB/Octave
Input Section 
Signal Input: 1x XLR fem, sym.
Network: RDnet, 2x RJ45
Signal Output: 1x Link XLR, male, sym, 1x X-Over Out, XLR male, sym.
Power Socket: Powercon In/Out
Voltage Range: 90 - 240 V
Mechanics 
Housing: Multiplex birch plywood
Housing Design: Rectangular
Color: Black
Surface Texture: Textured acrylic lacquer
Handles: 3x Per Side
Pole Mount: M20
Front Grille: 1.5mm metall grille
Rigging Points: 2xM10 on top to fix DRK10/20 rigging frames
Flytracks: No
Castors: Optional
Width: 580 mm (23.2 in)
Height: 800 mm (32 in)
Depth: 720 mm (28.8 in)
Weight: 52.5 kg (115.74 lbs)