LF
Sub-woofer
21"
21XR
Code: 21XRX8-347A
Sub-Woofer/21inch/Neo/Paper/1500W/8ohm
Key Features
- linear cone excursion 60mm peak TO peak !!
- unparallel low distortion at low frequencies
- patented design, innovative magnetic structure & venting system
Quick Specs
Impedance
8 Ω
Program Power
3600 W
Sensitivity
95.70 dB
Fs
32.30 Hz
Magnet
Neodymium
Voice Coil
134.6 mm
Design Notes
The 21XR is a high efficiency, (96 dB 1watt / 1 meter) 21-inch woofer with incredibly linear frequency response characteristics. Our new and patented ground up motor design is a new approach to high-excursion woofers. The voice coil winding is always in the magnetic gap that is extremely wide. This feature ensures extremely low distortion across whole working range of this unique driver.
Motor Design
The magnetic design incorporates large neodymium magnets placed along the voice coil winding. This has allowed us to push the cone excursion to 50mm peak to peak. Unique gap venting ensures good air circulation and greatly improves the reliability of this driver. We have also developed a new technique for manufacturing deep copper caps that are implemented in this design and covering the whole voice coil movement..
The design further utilizes triple, uncommonly large, spiders, spaced with spacers, hot-pressed tinsel wires onto the top spider, reinforced cone edge, reinforced surround to cone joint, reinforced spider to basket joints, etc.
Motor Design
The magnetic design incorporates large neodymium magnets placed along the voice coil winding. This has allowed us to push the cone excursion to 50mm peak to peak. Unique gap venting ensures good air circulation and greatly improves the reliability of this driver. We have also developed a new technique for manufacturing deep copper caps that are implemented in this design and covering the whole voice coil movement..
The design further utilizes triple, uncommonly large, spiders, spaced with spacers, hot-pressed tinsel wires onto the top spider, reinforced cone edge, reinforced surround to cone joint, reinforced spider to basket joints, etc.
Specifications
General Specs
Nominal Diameter
21"
Rated Impedance
8 Ohm
Magnet
Neodymium
Basket Material
Aluminum
Power Handling
AES Power
1800 W
Continuous Power
3600 W
Peak Power
7200 W
Voice Coil
Diameter
134.6 mm
Winding Wire
Copper
Former
Glass Fiber
Winding Height
21 mm
T/S Parameters
Resonant Frequency (Fs)
32.30 Hz
Re
4.50 \u2126
Qes
0.510
Qms
16.79
Qts
0.500
Vas
194.45 liters
Sd
1662.00 cm\u00B2
Mms
488.58 grams
Rms
5.90
Cms
0.0500
Bl
29.37 T\u00B7m
Le
0.650 mH
Sensitivity
95.70 dB
Design Details
Surround Material
fabric
Cone/Dome Material
Paper CF
Spider
Nomex
T-Plate
66.66 mm
Xmax (peak)
22.83 mm
Xmech
89.49 mm
Overall Diameter
549.00 mm
Bolt Circle Diameter
525.00 mm
Baffle Cutout Dia.
503.00 mm
Mounting Holes
8
Depth (flange to rear)
287.00 mm
Net Weight
23.80 kg
Ordering Codes
Product Code
21XRX8-347A
Downloads
Frequency Response & Impedance
2D Drawing
Enclosure Recommendations
Recommended enclosure alignments (bass reflex): - 105 liters tuned to 37 Hz: high output, strong mid-bass, reduced excursion; -3 dB approx. 34 Hz, HP filter 29 Hz - 120 liters tuned to 34 Hz: balanced response, general-purpose (recommended); -3 dB approx. 31 Hz, HP filter 24 Hz - 145 liters tuned to 31 Hz: extended low-frequency, requires HP filter protection; -3 dB approx. 26 Hz, HP filter 20 Hz
Frequently Asked Questions
- - linear cone excursion 60mm peak TO peak !!
- - unparallel low distortion at low frequencies
- - patented design, innovative magnetic structure & venting system
Recommended enclosure alignments (bass reflex): - 105 liters tuned to 37 Hz: high output, strong mid-bass, reduced excursion; -3 dB approx. 34 Hz, HP filter 29 Hz - 120 liters tuned to 34 Hz: balanced response, general-purpose (recommended); -3 dB approx. 31 Hz, HP filter 24 Hz - 145 liters tuned to 31 Hz: extended low-frequency, requires HP filter protection; -3 dB approx. 26 Hz, HP filter 20 Hz
Large-format vented or horn-loaded subwoofer / infra-bass; low-distortion excursion-critical applications; weight-critical installs
AES Power: 1800 W,
Continuous: 3600 W,
Peak: 7200 W.
Sensitivity: 95.70 dB (1W/1m).
