Memphis Audio MOJO MJM612 6.5-inch Subwoofer System Instruction Manual

1. Introduction

This manual provides detailed instructions for the installation, operation, and maintenance of your Memphis Audio MOJO MJM612 6.5-inch Subwoofer System. This system includes the Memphis Audio MOJO MJM612 subwoofer, a Rockville dB13 mono amplifier, and a Rockville RWK41 4-gauge wiring installation kit. The MOJO MJM612 subwoofer features Memphis FLEX™ technology, allowing selectable impedance of 1 Ohm or 2 Ohms for enhanced versatility. Please read this manual thoroughly before installation and use to ensure proper function and safety.

Figure 1.1: Overview of the Memphis Audio MOJO MJM612 subwoofer, Rockville dB13 amplifier, and Rockville RWK41 wiring kit.

2. Package Contents

Verify that all items listed below are present in your package. If any items are missing or damaged, contact your retailer immediately.

• (1) Memphis Audio MOJO MJM612 6.5-inch Competition Car Subwoofer (1 or 2 Ohm selectable)
• (1) Rockville dB13 3000 Watt Peak/750w RMS Mono 2 Ohm Amplifier
• (1) Rockville RWK41 4 Gauge Complete Car Amp Wiring Installation Wire Kit with RCA's
• (1) Amplifier Bass Remote
• (1) Amplifier Birth Sheet with Tested Power
• (1) Amplifier Owner's Manual
• (1) Set of Amplifier Mounting Screws
• (1) 17' High Grade Twisted Pair of 100% Copper RCA Cable
• (1) 17' 4 Gauge Translucent Blue SuperFlex Power Cable
• (1) 17' 18 Gauge Blue Remote Cable
• (1) 17' 16 Gauge Clear Speaker Wire
• (1) 3' 4 Gauge Clear SuperFlex Ground Wire
• (1) Gold Plated AGU Heat Resistant Fuse Holder
• (1) 100 Amp AGU Gold Plated Fuse
• (1) 60 Amp AGU Gold Plated Fuse
• (1) 7' Split Tube Loom
• Accessories Included: Wire Ties, Ring Terminals, Butt Connectors, Spades, and Grommets

Figure 2.1: Components of the Rockville RWK41 4-gauge wiring kit, including power cables, ground wire, RCA cables, speaker wire, fuse holder, and various terminals.

3. Product Features

3.1 Memphis Audio MOJO MJM612 Subwoofer

The MOJO MJM612 is a high-performance 6.5-inch subwoofer designed for competition-level car audio. It incorporates advanced features for durability and sound quality.

• FLEX™ Selectable Impedance: Allows selection between 1 Ohm or 2 Ohm impedance to match various amplifier configurations.
• CCAW Triple Voice Coil: Features a 1.5-inch Copper Clad Aluminum Wire (CCAW) triple voice coil for robust power handling.
• Vented Cast Aluminum Basket: Provides structural integrity and aids in cooling the voice coil.
• Double Stitched V-Groove Rubber Surround: Increases excursion capability without compromising effective surface area.
• DVVC Direct Vent Voice Coil Cooling: Enhances thermal management for sustained performance.
• Lightweight Ultra-Rigid Glass Fiber Dustcap: Contributes to accurate sound reproduction.
• Reinforced Spider: Ensures stability and longevity of the moving parts.

Figure 3.1.1: Top view of the MJM612 subwoofer, highlighting the V-Groove rubber surround and glass fiber dustcap.

Figure 3.1.2: Side view of the MJM612 subwoofer, showing the robust cast aluminum basket and overall construction.

3.2 Rockville dB13 Mono Amplifier

The Rockville dB13 is a powerful mono amplifier designed to drive subwoofers with high efficiency and clarity.

• High Power Output: Delivers 3000 Watts Peak and 750 Watts RMS at 2 Ohms (Dyno-Certified).
• Low THD+N: Less than 1% Total Harmonic Distortion plus Noise for clean audio.
• Mono Channel Design: Optimized for subwoofer applications.
• Bass Remote: Included for convenient bass level adjustment.

Figure 3.2.1: The Rockville dB13 mono amplifier, featuring its control panel and included bass remote.

3.3 Rockville RWK41 4 Gauge Wiring Kit

The RWK41 kit provides all necessary wiring and accessories for a complete amplifier installation.

• High-Quality Cables: Includes 100% copper RCA cables and SuperFlex power/ground cables.
• Comprehensive Set: Contains power cable, ground wire, remote wire, speaker wire, RCA cables, fuse holder, fuses, and various terminals/accessories.
• Safety Features: Gold-plated AGU heat-resistant fuse holder with 100 Amp and 60 Amp fuses.

4. Setup & Installation

Proper installation is crucial for optimal performance and safety. If you are unsure about any step, consult a professional car audio installer.

4.1 Safety Precautions

• Disconnect the vehicle's negative battery terminal before starting any electrical work.
• Wear appropriate safety gear, including eye protection.
• Ensure all wiring is properly routed and secured to prevent damage or short circuits.
• Use the correct fuse rating as specified.

4.2 Subwoofer Impedance Selection (MJM612)

The MOJO MJM612 subwoofer features a FLEX™ impedance selector switch, allowing you to choose between 1 Ohm or 2 Ohm operation. This selection must be made before connecting the subwoofer to the amplifier and should match the amplifier's stable impedance rating for optimal power delivery.

1. Locate the impedance selector switch on the subwoofer's terminal plate.
2. Using a small screwdriver or similar tool, carefully slide the switch to either the "1Ω WIRING" or "2Ω WIRING" position, depending on your amplifier's requirements.
3. Ensure the switch is fully engaged in the desired position.

Figure 4.2.1: The FLEX™ impedance selector switch on the MJM612 subwoofer, allowing selection between 1 Ohm and 2 Ohm wiring configurations.

4.3 Wiring Connections

Follow these general steps for connecting the system. Refer to the specific manuals for your vehicle and head unit for detailed instructions.

1. Power Cable (RWK41):
   • Run the 4-gauge translucent blue power cable from the vehicle's positive battery terminal to the amplifier's "BATT+" or "POWER" terminal.
   • Install the AGU fuse holder within 18 inches of the battery, using the appropriate fuse (e.g., 100 Amp for this system).
   • Ensure the cable is protected from sharp edges and heat.
2. Ground Cable (RWK41):
   • Connect the 4-gauge clear ground wire from the amplifier's "GND" or "GROUND" terminal to a clean, unpainted metal surface on the vehicle chassis.
   • The ground point should be as short as possible (less than 3 feet) and provide a solid electrical connection.
3. Remote Turn-On Cable (RWK41):
   • Connect the 18-gauge blue remote cable from your head unit's remote output to the amplifier's "REM" or "REMOTE" terminal. This cable turns the amplifier on and off with your head unit.
4. RCA Audio Cables (RWK41):
   • Connect the twisted pair RCA cables from your head unit's subwoofer pre-out (or full-range pre-out if no dedicated subwoofer output) to the amplifier's RCA input jacks.
5. Speaker Wire (RWK41 & MJM612):
   • Connect the 16-gauge clear speaker wire from the amplifier's speaker output terminals to the MJM612 subwoofer's terminals.
   • Ensure correct polarity (+ to + and - to -).
   • Double-check the subwoofer's impedance selection matches the amplifier's stable output impedance.

Figure 4.3.1: Close-up of the MJM612 subwoofer's push-style terminal connections for speaker wire input.

Figure 4.3.2: Another view of the MJM612 subwoofer's speaker terminals, showing positive (red) and negative (black) connections.

5. Operating Instructions

Once the system is installed, follow these steps for initial power-up and basic operation.

5.1 Initial Power-Up and Testing

1. Reconnect the vehicle's negative battery terminal.
2. Turn on your vehicle's ignition and head unit. The amplifier should power on (indicated by an LED on the amplifier).
3. Start with the amplifier's gain control set to minimum.
4. Play a familiar audio track with bass content at a moderate volume level on your head unit.
5. Slowly increase the amplifier's gain control until the desired bass level is achieved without distortion. Avoid setting the gain too high, as this can cause clipping and damage to the subwoofer or amplifier.
6. Adjust the bass remote for convenient level control from the driver's seat.

5.2 Amplifier Settings (Rockville dB13)

The Rockville dB13 amplifier typically includes controls for fine-tuning the subwoofer's output. Refer to the amplifier's specific manual for detailed adjustment procedures.

• Gain Control: Matches the amplifier's input sensitivity to the head unit's output voltage.
• Low Pass Filter (LPF): Sets the upper frequency limit for the subwoofer, ensuring it only plays bass frequencies.
• Subsonic Filter: Filters out extremely low frequencies that are inaudible and can waste amplifier power or damage the subwoofer.
• Bass Boost: Provides an adjustable boost at a specific bass frequency. Use sparingly to avoid distortion.

6. Maintenance

Regular maintenance helps ensure the longevity and optimal performance of your car audio system.

• Cleaning: Periodically clean the exterior of the subwoofer and amplifier with a soft, dry cloth. Avoid using harsh chemicals or abrasive cleaners.
• Connection Checks: Annually inspect all wiring connections (power, ground, remote, RCA, speaker) to ensure they are secure and free from corrosion. Loose connections can lead to poor performance or damage.
• Ventilation: Ensure the amplifier has adequate ventilation. Do not block cooling fins or mount in enclosed spaces without airflow.
• Subwoofer Inspection: Check the subwoofer cone and surround for any signs of damage or wear.

7. Troubleshooting

If you experience issues with your system, refer to the following common troubleshooting steps before seeking professional assistance.

7.1 No Power to Amplifier

• Check the in-line fuse near the battery. Replace if blown.
• Verify the power and ground connections at the amplifier and battery/chassis.
• Ensure the remote turn-on wire is connected and receiving 12V from the head unit when it's on.

7.2 No Sound from Subwoofer

• Confirm the amplifier is powered on (check LED indicator).
• Check RCA cable connections at both the head unit and amplifier.
• Verify speaker wire connections at both the amplifier and subwoofer, ensuring correct polarity.
• Ensure the head unit's subwoofer output is enabled and volume is up.
• Check amplifier gain settings; ensure it's not set to minimum.

7.3 Distorted Sound

• Reduce the amplifier's gain setting.
• Lower the head unit's volume.
• Check for loose speaker wires or short circuits.
• Ensure the subwoofer's impedance selection matches the amplifier's stable output.
• Verify that the subwoofer cone is not damaged or obstructed.

7.4 Amplifier Overheating

• Ensure adequate ventilation around the amplifier.
• Check the subwoofer's impedance setting; running below the amplifier's stable impedance can cause overheating.
• Reduce the gain setting.
• Verify proper ground connection.

8. Specifications

8.1 Memphis Audio MOJO MJM612 Subwoofer

8.2 Rockville dB13 Mono Amplifier

8.3 General System Specifications

9. Warranty Information

Memphis Audio products are warranted against defects in material or workmanship for a specified period from the date of purchase. This warranty is void if the product has been physically damaged by improper use or abuse, or if repairs have been attempted outside of a Memphis Audio repair facility.

This warranty is limited to the original retail purchaser and does not cover any expense incurred in the removal or reinstallation of the product. The warranty does not apply to product exterior and cosmetics. Memphis Audio disclaims any liability for incidental or consequential damages caused by product defects. Memphis Audio's liability will not exceed the purchase price of the product and the warranty period specified.

What is NOT Covered under this Warranty:

• Damage due to improper installation.
• Damage caused by exposure to moisture, excessive heat, chemical cleaners, and/or UV radiation.
• Damage through negligence, misuse, accident, or abuse. Repeated returns for the same damage may be considered abuse.
• Product damage as an accident due to criminal activity.
• Service performed by anyone other than Memphis Audio.
• Subsequent damage to other components.
• Any cost or expense related to the removal or re-installation of product.
• Speakers damaged due to amplifier clipping or distortion.
• Products with tampered, missing, altered, or defaced serial or model labels.
• Freight damage.
• The cost of shipping products to Memphis Audio.
• Return shipping on non-defective items.
• Any product not purchased from an authorized Memphis Audio dealer.

Some states do not allow for the exclusion or limitation of incidental or consequential damages, so the above limitations or exclusions may not apply to you. This warranty grants you specific rights and you may have other rights which vary from state to state.

If warranty service is required, a return authorization number is required. Contact Memphis Audio for details. Warranty shipments to Memphis Audio are the responsibility of the purchaser. Pack the product carefully in its original carton if possible. Memphis Audio will NOT be responsible for damages incurred in shipment or due to improper packaging materials used by the purchaser.

If determined to be in warranty, product will be repaired or replaced at the discretion of Memphis Audio.

Figure 9.1: Example of the Memphis Audio MOJO Mini Limited Warranty card.

10. Support & Contact

For technical assistance, warranty claims, or further information, please contact Memphis Audio customer support. Refer to the official Memphis Audio website or your purchase documentation for the most current contact information.

Online Resources: Visit the Memphis Audio Store on Amazon