Memphis Audio MJP1244 MOJO Pro 12-inch Car Subwoofer Instruction Manual

1. Introduction

This manual provides essential information for the proper installation, operation, and maintenance of your Memphis Audio MJP1244 MOJO Pro 12-inch Car Subwoofer. Please read this manual thoroughly before attempting installation or use to ensure optimal performance and safety.

1.1 Product Overview

The Memphis Audio MJP1244 MOJO Pro is a 12-inch subwoofer designed for car audio applications. It features a rigid paper cone, a die-cast aluminum basket, and dual 4-ohm voice coils. The subwoofer is engineered to handle up to 750 watts RMS (1500 watts peak) and incorporates Direct Vent Voice Coil Cooling (DVCC) for thermal management.

Figure 1.1: Front view of the Memphis Audio MJP1244 MOJO Pro 12-inch Subwoofer.

1.2 Key Features

• 12-inch subwoofer with dual 4-ohm voice coils
• Rigid paper cone with double-stitched foam surround
• Vented die-cast aluminum basket
• Designed for high Sound Pressure Level (SPL) performance
• Can be wired for 2-ohm or 8-ohm impedance
• Power handling: 750 watts RMS (1500 watts peak)

2. Safety Information

Please observe the following safety precautions during installation and operation:

• Professional Installation Recommended: Installation of car audio components can be complex. If you are unsure about any part of the installation process, seek assistance from a qualified professional installer.
• Electrical Safety: Always disconnect the vehicle's battery negative terminal before beginning any electrical work to prevent short circuits and electrical shock.
• Wiring: Ensure all wiring is correctly routed and secured to prevent damage from pinching, abrasion, or heat. Use appropriate gauge wire for power and speaker connections.
• Hearing Protection: Prolonged exposure to high sound pressure levels can cause permanent hearing damage. Use caution when operating your audio system at high volumes.
• Mounting: Securely mount the subwoofer and its enclosure to prevent movement during vehicle operation, which could cause injury or damage.
• Ventilation: Ensure adequate ventilation around the subwoofer and amplifier to prevent overheating.

3. Package Contents

Verify that your package contains the following items:

• Memphis Audio MJP1244 MOJO Pro 12-inch Subwoofer
• Instruction Manual (this document)
• Mounting hardware (if included with your specific purchase)

4. Setup and Installation

4.1 Mounting

The MJP1244 subwoofer requires a custom enclosure for optimal performance. Refer to the specifications section for recommended sealed and ported box volumes. Ensure the enclosure is robust and properly sealed.

• Cutout Diameter: The recommended cutout diameter for mounting is 11.122 inches.
• Mounting Depth: The subwoofer has a mounting depth of 6.23 inches. Ensure your chosen enclosure provides sufficient depth.
• Secure the subwoofer to the enclosure using appropriate screws, ensuring a tight, airtight seal.

Figure 4.1: Side view of the MJP1244 subwoofer, illustrating its mounting depth.

4.2 Wiring Configurations

The MJP1244 features dual 4-ohm voice coils, allowing for flexible wiring options to match your amplifier's impedance requirements. Common configurations include 2-ohm or 8-ohm impedance.

Figure 4.2: Close-up view of the MJP1244 subwoofer's dual voice coil terminals.

Important: Always verify your amplifier's stable impedance range before wiring. Incorrect wiring can damage your amplifier or subwoofer.

4.2.1 Parallel Wiring for 2-ohm Load

To achieve a 2-ohm load, connect the positive terminal of Voice Coil 1 to the positive terminal of Voice Coil 2. Then, connect the negative terminal of Voice Coil 1 to the negative terminal of Voice Coil 2. Finally, connect the combined positive terminals to the amplifier's positive output and the combined negative terminals to the amplifier's negative output.

4.2.2 Series Wiring for 8-ohm Load

To achieve an 8-ohm load, connect the positive terminal of Voice Coil 1 to the amplifier's positive output. Connect the negative terminal of Voice Coil 1 to the positive terminal of Voice Coil 2. Finally, connect the negative terminal of Voice Coil 2 to the amplifier's negative output.

4.3 Enclosure Recommendations

• Sealed Box Volume: 1.5 cubic feet
• Ported Box Volume: 2.5 cubic feet

5. Operating Guidelines

5.1 Power Handling

The MJP1244 subwoofer is rated for 750 watts RMS (Root Mean Square) and 1500 watts peak power. Ensure your amplifier's output power matches these specifications to prevent damage and achieve optimal performance. Underpowering a subwoofer can be as damaging as overpowering it, as it can lead to amplifier clipping and distorted signals.

5.2 Break-in Period

Allow a break-in period of approximately 10-20 hours of normal listening before operating the subwoofer at its maximum potential. This allows the suspension components (surround and spider) to loosen up and reach their optimal compliance, improving overall performance and longevity.

5.3 Amplifier Matching

Select an amplifier that can deliver the recommended RMS power to the subwoofer at the chosen impedance. Consult your amplifier's manual for its power output ratings at different impedances.

6. Maintenance

The Memphis Audio MJP1244 subwoofer requires minimal maintenance. Follow these guidelines to ensure its longevity:

• Cleaning: Use a soft, dry cloth to gently wipe the cone and surround. Avoid using harsh chemicals or excessive moisture.
• Inspection: Periodically inspect the subwoofer for any signs of damage to the cone, surround, or terminals. Check all wiring connections for tightness and corrosion.
• Environment: Protect the subwoofer from extreme temperatures, direct sunlight, and moisture.

7. Troubleshooting

If you experience issues with your MJP1244 subwoofer, refer to the table below for common problems and their solutions.

8. Specifications

The following are the technical specifications for the Memphis Audio MJP1244 MOJO Pro 12-inch Subwoofer:

Figure 8.1: Bottom view of the MJP1244 subwoofer, showing model and power ratings.

9. Warranty and Support

9.1 Limited Warranty

The Memphis Audio MJP1244 MOJO Pro subwoofer comes with a limited warranty. Please refer to the warranty card included with your product or visit the official Memphis Audio website for detailed terms and conditions regarding warranty coverage, duration, and claims procedures.

9.2 Customer Support

For technical assistance, troubleshooting beyond this manual, or warranty inquiries, please contact Memphis Audio customer support. You can find contact information and additional resources on the official Memphis Audio website: Visit the Memphis Store