What are the key features of the REDCATT 18NPW?

The REDCATT 18NPW features: Strong glass fiber loaded cone; High temperature voice coil, double layer silicone spider; High power handling.

What are the power handling and sensitivity specifications of the 18NPW?

The 18NPW has an AES power rating of 1200 W, continuous power of 2400 W, peak power of 4800 W, and a sensitivity of 99.14 dB (1W/1m).

What are the Thiele-Small parameters of the 18NPW?

Key T/S parameters: Fs=36.00 Hz, Qts=0.278, Vas=211.50 liters, Sensitivity=99.14 dB, Bl=27.30 T·m, Xmax=4.85 mm. Magnet type: Neodymium.

18NPW - Woofer - Professional Loudspeaker Engineering

Name: 18NPW
Brand: REDCATT
SKU: 18NPWX8-017

Design Notes

The 18NPW is a high efficiency, (99 dB 1watt / 1 meter) 18-inch woofer with incredibly linear frequency response characteristics, extreme high power handling capability while generating low harmonic distortion artifacts. The 18NPW uses a lightweight, but strong, glass fiber loaded cone assembly along with a high excursion triple roll constant geometry surround. This combination provides remarkable strength, high efficiency and a peak to peak maximum excursion of 21.5mm.

Power Handling
At the core of the 18NPW is it’s voice coil technology featuring a composite Polyimide former material capable of withstanding peak temperatures in excess of 350°C, well beyond the thermal requirements of modern professional audio systems. The 18NPW delivers incredible performance.

REDCATT has implemented a double layer/silicone spider design to ensure long term Fs memory, consistency and diminish anomalies associated with spider deterioration. The sealed spider works as a air pump and pushes the air trough out motor to increase heat transfer and cooling of the parts.

Specifications

General Specs

Nominal Diameter 18"

Rated Impedance 8 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 23.7 mm

T/S Parameters

Resonant Frequency (Fs) 36.00 Hz

Re 5.10 \u2126

Qes 0.280

Qms 8.39

Qts 0.278

Vas 211.50 liters

Sd 1257.00 cm\u00B2

Mms 199.40 grams

Rms 5.40

Cms 0.1000

Bl 27.30 T\u00B7m

Le 1.510 mH

Sensitivity 99.14 dB

Design Details

Surround Material fabric

Cone/Dome Material Paper CF

Spider Nomex

T-Plate 14 mm

Xmax (peak) 4.85 mm

Xmech 18.85 mm

Overall Diameter 468.00 mm

Bolt Circle Diameter 442.00 mm

Baffle Cutout Dia. 426.00 mm

Mounting Holes 8

Depth (flange to rear) 189.00 mm

Net Weight 9.40 kg

Ordering Codes

Product Code 18NPWX8-017

Downloads

2D Drawing (PDF) 3D Model (STEP)

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: 18NPWX8-017
Driver: 18NPWX8-017 (18NPW) — 18" Woofer
Key T/S: Fs=36.0Hz, Qts=0.278, Vas=211.5L, Sens=99.14dB
Power: AES 1200W / Cont 2400W / Peak 4800W
Xmax=4.85mm, Sd=1257.0cm², Bl=27.3T·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: 210 liters
     Tuning (Fb): 37 Hz
     Est. -3dB: 34 Hz
     HP Filter: 29 Hz (24dB/oct recommended)
     Round Port: 125mm dia × 37mm long
     Slot Port: 341mm W × 75mm H × 135mm L
     Port Velocity: 11.5 m/s
     Notes: Strong mid-bass impact, reduced cone excursion, maximum output
  b) Balanced Response
     Net Volume: 245 liters
     Tuning (Fb): 32 Hz
     Est. -3dB: 27 Hz
     HP Filter: 22 Hz (24dB/oct recommended)
     Round Port: 125mm dia × 51mm long
     Slot Port: 341mm W × 75mm H × 164mm L
     Port Velocity: 10.1 m/s
     Notes: General-purpose PA/subwoofer, even response, good transient behavior
  c) Extended Low Frequency
     Net Volume: 275 liters
     Tuning (Fb): 29 Hz
     Est. -3dB: 25 Hz
     HP Filter: 20 Hz (24dB/oct recommended)
     Round Port: 125mm dia × 68mm long
     Slot Port: 341mm W × 75mm H × 200mm L
     Port Velocity: 9.0 m/s
     Notes: Deep bass extension, requires proper system protection below tuning
--- Summary ---
The 18NPWX8-017 is a 18-inch high-output woofer driver designed for professional subwoofer systems where high efficiency (99 dB 1W/1m) and maximum acoustic output are required. 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 210 to 275 liters, tuned between 29 and 37 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 20–29 Hz is recommended depending on enclosure tuning, along with proper limiting to manage thermal and mechanical stress. Typical operating bandwidth is 25–100 Hz, making it suitable for integration with mid-bass or full-range systems.

Frequently Asked Questions

- Strong glass fiber loaded cone
- High temperature voice coil, double layer silicone spider
- High power handling

ENCLOSURE RECOMMENDATIONS: 18NPWX8-017
Driver: 18NPWX8-017 (18NPW) — 18" Woofer
Key T/S: Fs=36.0Hz, Qts=0.278, Vas=211.5L, Sens=99.14dB
Power: AES 1200W / Cont 2400W / Peak 4800W
Xmax=4.85mm, Sd=1257.0cm², Bl=27.3T·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: 210 liters
     Tuning (Fb): 37 Hz
     Est. -3dB: 34 Hz
     HP Filter: 29 Hz (24dB/oct recommended)
     Round Port: 125mm dia × 37mm long
     Slot Port: 341mm W × 75mm H × 135mm L
     Port Velocity: 11.5 m/s
     Notes: Strong mid-bass impact, reduced cone excursion, maximum output
  b) Balanced Response
     Net Volume: 245 liters
     Tuning (Fb): 32 Hz
     Est. -3dB: 27 Hz
     HP Filter: 22 Hz (24dB/oct recommended)
     Round Port: 125mm dia × 51mm long
     Slot Port: 341mm W × 75mm H × 164mm L
     Port Velocity: 10.1 m/s
     Notes: General-purpose PA/subwoofer, even response, good transient behavior
  c) Extended Low Frequency
     Net Volume: 275 liters
     Tuning (Fb): 29 Hz
     Est. -3dB: 25 Hz
     HP Filter: 20 Hz (24dB/oct recommended)
     Round Port: 125mm dia × 68mm long
     Slot Port: 341mm W × 75mm H × 200mm L
     Port Velocity: 9.0 m/s
     Notes: Deep bass extension, requires proper system protection below tuning
--- Summary ---
The 18NPWX8-017 is a 18-inch high-output woofer driver...

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: 99.14 dB (1W/1m).

18NPW

Key Features

Quick Specs