1. Introduction
Thank you for choosing the Memphis Audio MOJO Pro MJP822 8-inch Competition Car Subwoofers. This manual provides essential information for the proper installation, operation, and maintenance of your new subwoofers. Designed for high-performance car audio systems, these subwoofers deliver powerful bass and are built for durability and serious sound pressure level (SPL) capability. Each subwoofer handles 750 watts RMS and 1500 watts peak power, featuring dual 2-ohm voice coils for flexible wiring configurations.
Please read this manual thoroughly before attempting installation or operation to ensure optimal performance and longevity of your product.
2. Safety Information
Always observe the following safety precautions to prevent injury or damage to your equipment:
- Professional Installation Recommended: Due to the complexity of car audio systems and high power requirements, professional installation is highly recommended. Improper installation can lead to serious damage to your vehicle's electrical system, the subwoofers, or other audio components.
- Electrical Safety: Disconnect the vehicle's battery before performing any electrical work. Ensure all wiring is properly insulated and secured to prevent short circuits. Use appropriate gauge wiring for power and speaker connections.
- Hearing Protection: High sound pressure levels can cause permanent hearing damage. Exercise caution when operating the system at high volumes.
- Secure Mounting: Ensure the subwoofers are securely mounted within their enclosure and the enclosure is firmly secured within the vehicle to prevent movement during driving or in the event of an accident.
- Ventilation: Ensure adequate ventilation around the subwoofer and amplifier to prevent overheating.
- Avoid Moisture: Do not expose the subwoofers to moisture or extreme temperatures. The product is not waterproof.
3. Product Overview
The Memphis Audio MOJO Pro MJP822 subwoofers are engineered for extreme bass output and reliability. Key features include:
- High Power Handling: Each subwoofer handles 750W RMS / 1500W peak power.
- Dual Voice Coils: Dual 2-ohm voice coils provide versatile wiring options to match various amplifier configurations.
- Advanced Cooling: Features DVVC (Direct Vent Voice Coil Cooling) for efficient thermal management during extended high-power use.
- Durable Construction: Equipped with a 2.5-inch voice coil, aluminum shorting ring, progressive spider, rigid paper cone, and a double-stitched foam surround for enhanced durability and performance.
- Robust Frame: A diecast aluminum basket ensures structural integrity and longevity.
- Optimized Magnet Structure: A 105 oz magnet provides strong motor force for precise and powerful bass reproduction.
4. Setup and Installation
Proper installation is crucial for the performance and longevity of your MOJO Pro subwoofers. It is highly recommended to have these subwoofers installed by a certified car audio professional.
4.1 Enclosure Requirements
The MJP822 subwoofers are designed to perform optimally in specific enclosure volumes:
- Sealed Enclosure: Recommended volume of 0.6 cubic feet per subwoofer. Sealed enclosures provide tight, accurate bass response.
- Vented (Ported) Enclosure: Recommended volume of 1.0 cubic feet per subwoofer. Vented enclosures typically offer higher SPL and deeper bass extension.
Consult with your installer or an audio specialist to determine the best enclosure type and design for your specific vehicle and listening preferences.
4.2 Wiring Dual Voice Coils (DVC 2 Ohm)
The MJP822 features dual 2-ohm voice coils, offering flexibility in wiring configurations to achieve different final impedances. Common wiring options include:
- Parallel Wiring (Single Subwoofer): Connect both 2-ohm voice coils in parallel to achieve a 1-ohm load. This configuration draws more current from the amplifier and is suitable for amplifiers stable at 1 ohm.
- Series Wiring (Single Subwoofer): Connect both 2-ohm voice coils in series to achieve a 4-ohm load. This configuration is easier on the amplifier and provides a cleaner signal for some setups.
- Multiple Subwoofer Configurations: When using two MJP822 subwoofers, various series and parallel combinations can achieve final impedances of 0.5 ohm, 2 ohm, or 8 ohm, depending on your amplifier's capabilities. Refer to your amplifier's manual for compatible impedance loads.
Always ensure your amplifier is stable at the final impedance load you choose. Incorrect impedance matching can lead to amplifier damage or poor performance.
4.3 Mounting
Mount the subwoofer securely within the designed enclosure. Ensure all mounting screws are tightened evenly to prevent air leaks and vibrations. The enclosure itself must be securely fastened within the vehicle to prevent movement during driving.
5. Operating Instructions
5.1 Break-In Period
Allow a break-in period of approximately 20-30 hours of normal listening before operating the subwoofers at their maximum potential. This allows the suspension components (surround and spider) to loosen up and reach their optimal compliance, improving overall performance and longevity.
5.2 Amplifier Gain Setting
Properly setting your amplifier's gain is critical. Do not use the gain control as a volume knob. It should be set to match the output voltage of your head unit. Setting the gain too high can lead to clipping, which sends a distorted signal to the subwoofer, causing damage.
- Start with the amplifier gain at its minimum.
- Play a test tone or music with a wide dynamic range at a moderate volume.
- Slowly increase the amplifier gain until you hear any distortion, then back off slightly.
- Consider using an oscilloscope or a digital multimeter for precise gain setting.
5.3 Crossover and Bass Boost Settings
Properly configure your amplifier's low-pass filter (LPF) to ensure the subwoofer only reproduces bass frequencies. Avoid excessive bass boost, as this can lead to over-excursion and damage, especially at high volumes.
6. Maintenance
The Memphis Audio MOJO Pro MJP822 subwoofers require minimal maintenance to ensure long-term performance:
- Cleaning: Periodically wipe down the subwoofer cone and surround with a soft, dry cloth to remove dust and debris. Do not use harsh chemicals or solvents.
- Inspection: Regularly inspect the subwoofer's surround for any signs of cracking or tearing. Check all wiring connections to ensure they are secure and free from corrosion.
- Environmental Conditions: Avoid exposing the subwoofers to extreme temperatures, direct sunlight for prolonged periods, or excessive moisture.
7. Troubleshooting
If you experience issues with your MOJO Pro subwoofers, refer to the following common troubleshooting steps:
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound from subwoofer |
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| Distorted or unclear bass |
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| Subwoofer overheating |
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If these steps do not resolve the issue, please contact Memphis Audio customer support or a qualified car audio technician.
8. Specifications
| Feature | Detail |
|---|---|
| Model Name | MJP822 |
| Speaker Type | Subwoofer |
| Speaker Size | 8 Inches |
| Woofer Diameter | 8 Inches |
| Speaker Maximum Output Power | 1500 Watts (Peak) |
| RMS Power Handling (Each) | 750 Watts |
| Impedance | Dual 2 Ohm (DVC 2 Ohm) |
| Material | Aluminum (Basket), Rigid Paper (Cone), Foam (Surround) |
| Color | Black |
| Product Dimensions (Each) | 9.8"D x 9.7"W x 8.5"H |
| Item Weight (Total for 2) | 35.2 Pounds |
| Manufacturer | MEMPHIS AUDIO |
| Compatible Devices | Car Audio System |
| Included Components | Subwoofer (x2) |
| Is Waterproof | FALSE |
| Recommended Sealed Enclosure Volume | 0.6 cu ft (per sub) |
| Recommended Vented Enclosure Volume | 1.0 cu ft (per sub) |
9. Warranty Information
The Memphis Audio MOJO Pro MJP822 subwoofers come with a Limited Warranty from the manufacturer, MEMPHIS AUDIO. The specific terms and duration of the warranty may vary. Please retain your proof of purchase for warranty claims.
For detailed warranty terms and conditions, please refer to the documentation included with your product or visit the official Memphis Audio website. Any additional protection plans, such as 2-Year or 3-Year plans, are typically offered by retailers or third-party providers and are separate from the manufacturer's warranty.
10. Support and Contact
For technical assistance, warranty inquiries, or further information regarding your Memphis Audio MOJO Pro MJP822 subwoofers, please contact:
Memphis Audio Customer Support:
- Visit the official Memphis Audio website for contact details, FAQs, and support resources.
- If purchased from a retailer, you may also contact their customer service for initial support.
When contacting support, please have your product model number (MJP822) and proof of purchase readily available.
