LF
Woofer
18"
181XR
Code: 181XRX4-350
XR Woofer/18inch/Neo/Paper/1200W/4ohm
Key Features
- Cone excursion 56mm !! Patented design.
- 1 demodulation copper ring, powerful and innovative motor structure, innovative venting system
- Double spider with spacer, woven-in tinsel wires, reinforced cone edge.
Quick Specs
Impedance
4 Ω
Program Power
2400 W
Sensitivity
96.54 dB
Fs
30.00 Hz
Magnet
Neodymium
Voice Coil
101.6 mm
Design Notes
Designed based upon the 18XR, the 181XR was designed for professional audio segment.
The basic characters and design concept remains the same for the 181XR. We have used newly designed 4 roll waterproof fabric surround that fully supports the high cone excursions of this incredible loudspeaker. The target was to push the envelope of possibilities. We are giving you a product that will not limit you to achieve even your wildest sub-woofer dreams.
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 44mm 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.
The design further utilizes dual, uncommonly large, spiders, spaced with spacer, hot-pressed tinsel wires onto the top spider, reinforced cone edge, reinforced surround to cone joint, reinforced spider to basket joints, etc.
The basic characters and design concept remains the same for the 181XR. We have used newly designed 4 roll waterproof fabric surround that fully supports the high cone excursions of this incredible loudspeaker. The target was to push the envelope of possibilities. We are giving you a product that will not limit you to achieve even your wildest sub-woofer dreams.
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 44mm 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.
The design further utilizes dual, uncommonly large, spiders, spaced with spacer, 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
18"
Rated Impedance
4 Ohm
Magnet
Neodymium
Basket Material
Aluminum
Power Handling
AES Power
1200 W
Continuous Power
2400 W
Peak Power
4800 W
Voice Coil
Diameter
101.6 mm
Winding Wire
Copper
Former
Glass Fiber
Winding Height
22 mm
T/S Parameters
Resonant Frequency (Fs)
30.00 Hz
Re
3.30 \u2126
Qes
0.240
Qms
13.20
Qts
0.230
Vas
195.00 liters
Sd
1256.60 cm\u00B2
Mms
306.00 grams
Rms
4.37
Cms
0.0900
Bl
28.30 T\u00B7m
Le
1.300 mH
Sensitivity
96.54 dB
Design Details
Surround Material
fabric
Cone/Dome Material
Paper GF
Spider
Nomex
T-Plate
56 mm
Xmax (peak)
17 mm
Xmech
36 mm
Overall Diameter
467.60 mm
Bolt Circle Diameter
442.00 mm
Baffle Cutout Dia.
422.00 mm
Mounting Holes
8
Depth (flange to rear)
257.20 mm
Net Weight
14.50 kg
Ordering Codes
Product Code
181XRX4-350
Downloads
Frequency Response & Impedance
2D Drawing
Technical Summary
This design is particularly effective in single or multi-driver bass reflex systems used in touring, installation, and high-SPL applications, where consistent performance, durability, and output capability are critical.
Enclosure Recommendations
ENCLOSURE RECOMMENDATIONS: 181XRX4-350
Driver: 181XRX4-350 (181XR) — 18" Sub-woofer
Key T/S: Fs=30.0Hz, Qts=0.23, Vas=195.0L, Sens=96.54dB
Power: AES 1200W / Cont 2400W / Peak 4800W
Xmax=17.00mm, Sd=1256.6cm², Bl=28.3T·m
RECOMMENDED ENCLOSURE TYPE: Bass Reflex (Vented)
PORT RECOMMENDATION: Slot port (full-width or L-shaped internal duct) — provides large cross-sectional area needed for high air displacement; reduces port noise at high SPL
a) High SPL
Net Volume: 230 liters
Tuning (Fb): 28 Hz
Est. -3dB: 24 Hz
HP Filter: 25 Hz (24dB/oct recommended)
Round Ports: 2× 125mm dia × 301mm long
Slot Port: 338mm W × 75mm H × 273mm L
Port Velocity: 15.5 m/s
Notes: Strong mid-bass impact, reduced cone excursion, maximum output
b) Balanced Response
Net Volume: 275 liters
Tuning (Fb): 25 Hz
Est. -3dB: 21 Hz
HP Filter: 22 Hz (24dB/oct recommended)
Round Ports: 2× 125mm dia × 343mm long
Slot Port: 338mm W × 75mm H × 317mm L
Port Velocity: 13.6 m/s
Notes: General-purpose PA/subwoofer, even response, good transient behavior
c) Extended Low Frequency
Net Volume: 275 liters
Tuning (Fb): 23 Hz
Est. -3dB: 20 Hz
HP Filter: 20 Hz (24dB/oct recommended)
Round Ports: 2× 125mm dia × 402mm long
Slot Port: 338mm W × 75mm H × 378mm L
Port Velocity: 12.7 m/s
Notes: Deep bass extension, requires proper system protection below tuning
--- Summary ---
The 181XRX4-350 is a 18-inch high-output sub-woofer driver designed for professional subwoofer systems requiring high sensitivity (97 dB 1W/1m) and controlled low-frequency behavior. The motor and suspension are optimized to maintain consistent performance at high drive levels, with controlled excursion and reduced thermal compression during long-term operation.
In bass reflex enclosures, the driver performs best in net internal volumes of 230 to 275 liters, tuned between 23 and 28 Hz. This alignment provides a balanced combination of low-frequency extension, cone control around resonance, and efficient port loading. Lower tuning improves deep bass extension but increases excursion below tuning, requiring appropriate high-pass filtering. Higher tuning increases sensitivity and output in the upper bass region while improving mechanical control.
The driver is intended for use with high-power amplification (approx. 1200 W AES / 2400 W continuous) and DSP control. A high-pass filter in the range of 20–25 Hz is recommended depending on enclosure tuning, along with proper limiting to manage thermal and mechanical stress. Typical operating bandwidth is 20–100 Hz, making it suitable for integration with mid-bass or full-range systems.
Frequently Asked Questions
- - Cone excursion 56mm !! Patented design.
- - 1 demodulation copper ring, powerful and innovative motor structure, innovative venting system
- - Double spider with spacer, woven-in tinsel wires, reinforced cone edge.
ENCLOSURE RECOMMENDATIONS: 181XRX4-350
Driver: 181XRX4-350 (181XR) — 18" Sub-woofer
Key T/S: Fs=30.0Hz, Qts=0.23, Vas=195.0L, Sens=96.54dB
Power: AES 1200W / Cont 2400W / Peak 4800W
Xmax=17.00mm, Sd=1256.6cm², Bl=28.3T·m
RECOMMENDED ENCLOSURE TYPE: Bass Reflex (Vented)
PORT RECOMMENDATION: Slot port (full-width or L-shaped internal duct) — provides large cross-sectional area needed for high air displacement; reduces port noise at high SPL
a) High SPL
Net Volume: 230 liters
Tuning (Fb): 28 Hz
Est. -3dB: 24 Hz
HP Filter: 25 Hz (24dB/oct recommended)
Round Ports: 2× 125mm dia × 301mm long
Slot Port: 338mm W × 75mm H × 273mm L
Port Velocity: 15.5 m/s
Notes: Strong mid-bass impact, reduced cone excursion, maximum output
b) Balanced Response
Net Volume: 275 liters
Tuning (Fb): 25 Hz
Est. -3dB: 21 Hz
HP Filter: 22 Hz (24dB/oct recommended)
Round Ports: 2× 125mm dia × 343mm long
Slot Port: 338mm W × 75mm H × 317mm L
Port Velocity: 13.6 m/s
Notes: General-purpose PA/subwoofer, even response, good transient behavior
c) Extended Low Frequency
Net Volume: 275 liters
Tuning (Fb): 23 Hz
Est. -3dB: 20 Hz
HP Filter: 20 Hz (24dB/oct recommended)
Round Ports: 2× 125mm dia × 402mm long
Slot Port: 338mm W × 75mm H × 378mm L
Port Velocity: 12.7 m/s
Notes: Deep bass extension, requires proper system protection below tuning
--- Summary ---
The 181XRX4-350 is a 18-inch high-o...
This design is particularly effective in single or multi-driver bass reflex systems used in touring, installation, and high-SPL applications, where consistent performance, durability, and output capability are critical.
AES Power: 1200 W,
Continuous: 2400 W,
Peak: 4800 W.
Sensitivity: 96.54 dB (1W/1m).
