Eighteen Sound 18NTLW5000.4 LF Driver User Manual

Introduction

This manual provides essential information for the proper installation, operation, and maintenance of your Eighteen Sound 18NTLW5000.4 LF Driver. The 18NTLW5000 is an 18-inch next-generation high-performance subwoofer, specifically designed for high SPL (Sound Pressure Level) and very low-frequency applications. It is suitable for use in either a reflex, bandpass, or horn-loaded configuration. This driver utilizes Eighteen Sound's proprietary Tetracoil technology, featuring two different, axially separated magnetic gaps and two inside-outside 4.5-inch diameter aluminum voice coils wound on the same former and suspended evenly in the two magnetic gaps. Its design ensures ultra-linear piston action and full mechanical control across the entire working range, even under inclement weather conditions due to its exclusive cone treatment.

Product Overview and Key Features

Figure 1: Front view of the Eighteen Sound 18NTLW5000.4 LF Driver, showcasing its robust design and voice coil.

The 18NTLW5000.4 is engineered for exceptional sound clarity and durability. Key features include:

• High Sensitivity: 95 dB SPL 1W / 1m average sensitivity, ensuring efficient power conversion into sound.
• Advanced Voice Coil: Features a dual 115mm (4.5 inch) Tetracoil Aluminum Voice coil for enhanced power handling and linearity.
• High Power Handling: Capable of handling 4000 W program power, with a nominal power handling of 1800 W.
• Linear Suspension: Ultra-linear suspension behavior provides excellent sound clarity and precise piston action across the working range.
• Optimized Magnetic System: Symmetric flux density and inductance behavior contribute to consistent performance.
• Efficient Cooling: Low noise forced air cooling design helps maintain optimal operating temperatures.
• Durable Construction: Water repellent cone and epoxy coated plates ensure reliability in various environmental conditions.
• Versatile Application: Suitable for vented, horn loaded, and bandpass applications.

Figure 2: Rear view of the Eighteen Sound 18NTLW5000.4 LF Driver, showing the robust frame and cooling structure.

Setup and Installation

Proper installation is crucial for optimal performance and longevity of the 18NTLW5000.4 LF Driver. This driver is designed for integration into custom speaker enclosures.

Enclosure Recommendations:

• Recommended Enclosure Volume: 180.0 dm³ (6.36 ft³).
• Recommended Tuning Frequency: 35 Hz.
• The driver is suitable for vented, horn-loaded, and bandpass applications. Consult professional audio system designers for specific enclosure designs tailored to your application.

Mounting Information:

• Overall Diameter: 462 mm (18.19 in)
• Bolt Circle Diameter: 440 mm (17.32 in)
• Baffle Cutout Diameter: 416.0 mm (16.38 in)
• Depth: 310 mm (12.2 in)
• Flange and Gasket Thickness: 26 mm (1.02 in)

Ensure the mounting surface is flat and secure. Use appropriate fasteners to firmly attach the driver to the enclosure baffle. Maintain proper air sealing around the driver to prevent air leaks that can degrade performance.

Operating Guidelines

The 18NTLW5000.4 is a passive component designed to be driven by an external amplifier. Adhere to the following guidelines for safe and optimal operation:

• Amplifier Matching: Use an amplifier that can provide sufficient power for the driver's nominal (1800 W) and continuous (4000 W) power handling capabilities, while respecting its 4 Ohm nominal impedance. Mismatched impedance or underpowering can lead to distortion and potential damage.
• Cabling: Use high-quality speaker cables of appropriate gauge to minimize power loss and ensure signal integrity.
• Signal Processing: Implement appropriate crossover frequencies and equalization to protect the driver from frequencies outside its optimal range (35 - 1000 Hz) and to achieve desired sound characteristics.
• Monitoring: Listen for signs of distortion or stress from the driver. If distortion is heard, reduce the input level immediately.

Maintenance

The 18NTLW5000.4 LF Driver is built for durability and requires minimal maintenance. However, following these simple steps can extend its lifespan and maintain performance:

• Cleaning: Periodically inspect the cone and surround for dust or debris. Gently clean with a soft, dry cloth. Avoid using harsh chemicals or excessive moisture.
• Environmental Protection: While the cone is water and UV repellent, prolonged exposure to extreme moisture, direct sunlight, or harsh chemicals should be avoided to preserve the integrity of the materials.
• Physical Inspection: Regularly check for any signs of physical damage to the cone, surround, or frame. Ensure all mounting bolts remain secure.

Troubleshooting

If you experience issues with your 18NTLW5000.4 LF Driver, consider the following common troubleshooting steps:

• No Sound:
  • Verify all cable connections from the amplifier to the driver are secure and correctly polarized (+ to + and - to -).
  • Check the amplifier's power and signal status.
  • Ensure the audio source is active and sending a signal.
• Distorted Sound:
  • Reduce the volume level from the amplifier or source. Overdriving the driver can cause distortion.
  • Check for proper amplifier gain staging.
  • Inspect the driver's cone and surround for any physical damage or obstructions.
  • Ensure the enclosure is properly sealed and free of air leaks.
• Low Output:
  • Confirm the amplifier's power output is adequate for the driver.
  • Check the impedance matching between the amplifier and the driver.
  • Verify crossover settings are not too high, limiting the low-frequency output.

If problems persist after attempting these steps, contact a qualified audio technician or Eighteen Sound customer support for further assistance.

Technical Specifications

Performance Graphs:

Figure 3: Frequency Response Curve. Measured in 180 Lt. enclosure tuned at 34 Hz in free field (4π) environment. Enclosure closes the rear of the driver.

Figure 4: Free Air Impedance Curve.

Warranty and Support

The Eighteen Sound 18NTLW5000.4 LF Driver comes with a Full Warranty. For specific terms and conditions of the warranty, please refer to the documentation provided with your purchase or visit the official Eighteen Sound website.

For technical support, service, or warranty claims, please contact Eighteen Sound customer service. When contacting support, please have your product model number (18NTLW5000.4) and purchase information readily available.

Eighteen Sound Official Website: www.eighteensound.it (Note: This is a placeholder URL as no official support link was provided in the input data. Users should refer to their purchase documentation for precise support contact information.)