NEX D MX6003 600W 3-Channel Class D System Amplifier Owner’s Manual
- June 5, 2024
- NEX D
Table of Contents
OWNER’S MANUAL
MX600/3
600W 3-Channel Class D System Amplifier
Thank you for purchasing a JL Audio amplifier for your sound system.
Your amplifier has been designed and manufactured to exacting standards in
order to ensure years of musical enjoyment. For maximum performance, we highly
recommend that you have your new amplifier installed by an authorized JL Audio
dealer. Your authorized dealer has the training, expertise, and installation
equipment to ensure optimum performance from this product. Should you decide
to install the amplifier yourself, please take the time to read this manual
thoroughly to familiarize yourself with its installation requirements and
setup procedures.
If you have any questions regarding the instructions in this manual or any
aspect of your amplifier’s operation, please contact your authorized JL Audio
dealer for assistance. If you need further assistance, please call the JL
Audio Technical Support Department at
technical@jlaudio.com or call (954) 443–1100
during business hours.
What’s Included
(1) Amplifier
(4) Stainless steel mounting screws
(1) User manual
Product Description
This is a three-channel, system amplifier utilizing Class D technology for all channels.
Installation Applications
This amplifier is designed for operation with 12 volts, negative ground
electrical systems. Using this product in systems with the positive ground
and/or voltages other than 12V may result in damage to the product and will
void the warranty.
This product is not certified or approved for use in aircraft.
Safety Considerations
-
Whenever possible, mount the amplifier in a dry, well-ventilated location that does not interfere with other factory-installed electronic devices. If a dry environment is not available, a location that is not exposed to heavy splashing may be used.
-
While this amplifier is designed to be water-resistant, it should never be submerged under water or subjected to high-pressure water spray.
Do not install where it will be directly exposed to the elements. -
Do not mount the amplifier in the engine compartment or in any areas of extreme heat.
-
Securely mount the amplifier so that it does not come loose in the event of a collision/sudden jolt or as a result of repeated vibrations during normal operation.
-
Check before drilling to make sure that you will not be drilling into an exterior panel/hull, fuel tank, gas/brake line, wiring harness, or another vital system.
-
Do not run system wiring outside or underneath the vehicle/vessel. This is an extremely dangerous practice, which can result in severe damage/injury.
-
Protect all system wires from sharp edges (metal, fiberglass, etc.) by carefully routing them, tying them down, and using grommets and loom where appropriate.
-
Secure all wiring as needed, using cable ties or wire clamps to protect them from moving parts and sharp edges.
IPX7 Water Resistance Rating
This product has been tested to withstand immersion in water, up to 1 meter
(3.28 ft.) deep, for up to 30 minutes (with the control panel cover properly
installed).
Note – while designed to be water resistant, this product should never be
submerged under water for prolonged periods or subjected to activity that
creates pressure on it that exceeds its depth rating.
Installation Procedure/Connections
-
Disconnect the NEGATIVE battery post connection and secure the disconnected cable to prevent accidental reconnection during installation.
This is an essential safety precaution during installation! -
Connect the RED power lead to the positive (+12V) battery post. 4 AWG is the minimum power wire size for this amplifier.
-
An appropriate fuse (sold separately), such as the JL Audio Water-Resistant Master MAXI™ Fuse Block (XD-MFBW-MAXI), at the main power wire(s) to the amplifier(s) is vital for vehicle/vessel safety. This fuse must be installed within 18 inches (45 cm) of the positive battery post connection. If this is the only device connected to this main wire, use a 60A fuse. Do not install the fuse until the power wire has been securely connected to the amplifier.
-
Connect the BLACK negative ground lead to a clean, solid metal grounding point near the amplifier. This can be to metal chassis ground, if available.
If no metal chassis ground is available, it may be necessary to make this connection to the NEGATIVE battery post. 4 AWG is the minimum ground wire size for this amplifier. All ground connections (source unit and amplifiers) should be made at the same location. -
Connect the BLUE remote turn-on lead to the source unit’s positive (+12V) remote turn-on output. If your source unit does not have a dedicated remote turn-on output, the amplifier’s turn-on lead can be connected to +12V via a switch that derives power from an ignition-switched circuit.
-
Signal Input (Low-Level): Connect the amplifier’s RCA input jacks to the source unit’s preamp level output jacks.
-
Signal Input (High-Level): If your source unit does not offer preamp level signal outputs, you can splice the speaker output wires of the source unit onto a pair of RCA plugs for each input pair or use the JL Audio ECS Speaker Wire to RCA adaptor (XD-CLRAIC2-SW). Make sure to observe correct polarity in making “High-Level Input” connections. Failure to do so will result in a loss of signal (poor performance).
-
Connect the speaker output leads to the corresponding speaker wires.
-
Make necessary adjustments to the filter controls and input sensitivity.
-
The amplifier’s subwoofer output level can be controlled from the front of the vehicle/vessel with an optional remote level controller (sold separately). Use the RBC-1 for standard (dry) installations or the M-RBC-1 for applications exposed to moisture. Connect the remote’s plug to the amplifier’s harness-mounted RJ11 input jack. (Refer to Appendix B)
WARNING! Failure to make safe, tight, high-integrity power connections can result in fire and extensive damage!
Wiring Diagram
Power Connections
Label| Wire Color| Description
+12V| Red| Positive (+12V) Power Connection
GND| Black| Negative (GND) Ground Connection
REM| Blue| Positive (+12V) Remote Turn-On Input
Inputs
Label| Plug| Description
FRONT
IN| White RCA| Ch. 1 / Front Left Channel Signal Input
Red RCA| Ch. 2 / Front Right Channel Signal Input
SUB
IN| White RCA| Ch. 3 / Left Subwoofer Note: L & R Sub Channel Signal Input
combined to| Note: L & R Sub Inputs will be combined to mono. If only one
channel of subwoofer signal is available, we recommend using a
Y-adaptor to feed both Sub Inputs.
Red RCA| channel of subwoofer
Ch. 4 / Right Subwoofer available, we Channel Signal Input Y-adaptor to
Outputs
Label| Wire Color| | Description
FL+| White| Ch. 1| (+) Positive Front Left Speaker| Front Bridged (+)
FL-| White/Black| (-) Negative Front Left Speaker
FR+| Gray| Ch. 2| (+) Positive Front Right Speaker
FR-| Gray/Black| (-) Negative Front Right Speaker| Front Bridged (-)
SUB+| Lt. Blue| Ch. 3| (+) Positive Subwoofer Output
SUB-| Lt. Blue/Black| (-) Negative Subwoofer Output
Optional
Remote Bass Control Jack| RJ11 Input Jack for M-RBC-1 or RBC-1 (each sold separately)
Control Panel Settings and Adjustments
The amplifier’s settings and controls are located on the bottom panel beneath
a gasket, protective cover. Remove the four Phillips head screws from the
center panel to access the controls and make adjustments. Replace the cover
when finished and mount the amplifier.
Control| Setting|
Mode / Function
---|---|---
Front / Subwoofer| Input
Voltage| Low| RCA/Preamp Level Range (250 mV – 4 V)
High| RCA/Preamp or Speaker Level Range (580 mV – 14 V)
Input
Sens.| Variable| Adjusts the input stage of each pair of amplifier channels to
match the source unit’s output voltage for maximum clean output (refer to
Appendix A)
Front| Input
Mode| 2CH| Applies two channels of input to all three amplifier channels. Main
input signals will be combined to mono for the subwoofer channel.| Use Front
Inputs Only
4CH| Sends four discrete channels to all four inputs. L & R Sub Inputs will be
combined to mono.
If only one channel of subwoofer signal is available, we recommend using a
V-adaptor to feed both Sub Inputs.| Use Front and Sub Inputs
Filter
Freq. (Hz)| Variable| Adjusts the high-pass filter cutoff frequency, variable
from 35-300 Hz, 12 dB/Octave
Subwoofer| Output
Polarity| 0| Normal speaker polarity
180 deg.| Polarity reversed 180 degrees
Infrasonic
Filter (Hz)| Variable| Adjusts the high-pass filter cutoff frequency, variable
from 20-40 Hz, 12 dB/Octave
LP Alter Freq. (Hz)| Variable| Adjusts the low-pass filter cutoff frequency,
variable from 40-400 Hz, 24 dB/Octave
Bass
Boost (dB)| Variable| Boost-Only Bass Equalizer: Boost range from 0dB (full-
counterclockwise) to + 12dB (full-clockwise), centered at 43 Hz.
Status LED’s / Protection Circuitry
There are two status indicator lights on the wiring end panel of the
amplifier.
- “POWER” (Green): Lights to indicate that the amplifier is turned on and operating normally.
- “PROTECT” (Red): Lights to indicate the amplifier’s protection circuitry has been triggered to prevent product failure due to any conditions noted in the chart below. When a protection mode is activated, the amplifier will shut down to protect its circuitry. For Thermal Protection, Over Current, and Short Circuit conditions, the amplifier will resume normal operation once the problem is corrected, with the “Protect” LED turning off. For Over Voltage conditions, the amplifier must be turned off/on to return to normal operation. Note: connecting the speaker outputs to impedances lower than 2 ohms (4 ohms bridged) will also cause this protection mode to activate.
POWER
(Green LED)| PROTECT (Red LED)| Status/Condition| Note
---|---|---|---
ON| OFF| Normal Operation|
OFF| ON| Thermal Protection| Lasts until temp cools to normal
OFF/ON| ON/OFF| Over Current| Green/Red LEDs alternate for 1 second
OFF| ON| Short Circuit| Possible audible “popping” noise
OFF| ON| Over Voltage| Turn amp off/on to restart
Specifications| MX600/3
---|---
Rated RMS Power @ 14.4V, <10/0THD+N| Main@ 4Ω| Main @ 2Ω| Main @ 4Ω
Bridged| Sub@ 4Ω| Sub@ 3Ω| Sub@ 2Ω
75Wx 2| 100Wx 2| 200Wx 1| 250Wx1| 300Wx 1| 400Wx1
Rated RMS Power @ 12.5V, <113/o THD+N| Main@ 4Ω| Main @ 2Ω| Main @ 4Ω Bridged|
Sub@ 4Ω| Sub@ 3Ω| Sub@ 2Ω
50Wx2| 80Wx2| 160Wx1| 200Wx1| 250Wx 1| 300Wx1
Frequency Response| 20 Hz – 20 kHz (+0, -1dB), 6.3 Hz – 30 kHz (+0, -3dB)
S/N Ratio, A-weighted, 20 kHz noise bandwidth| 88 dB (Referred to as rated
power), 68 dB (Referred to as 1 W)
Damping Factor| >92 / 50 Hz @ 4 Ω, >43 / 50 Hz @ 2Ω
Input Voltage Range| 250 mV – 4 V (Low) or 580 mV – 14 V (High)
Input Mode Switch| 2 / 4 Channel
Front High-Pass Filter| Freq. Range: 35 – 300 Hz| Slope: 12 dB/Octave
Sub Low-Pass Filter| Freq. Range: 40 – 400 Hz| Slope: 24 dB/Octave
Infrasonic Filter| Freq. Range: 20 – 40 Hz| Slope: 12 dB/Octave
Sub Output Polarity| 0 or 180 degrees
Bass Boost EQ| 0 to +12 dB @ 43 Hz
Remote Bass Controller| M-RBC-1 or RBC-1 (sold separately)
Input Operating Voltage| 11 -15 VDC
Min Power/GND Wire| 4 AWG
Fuse Rating| 60A
Dimensions| 9.33 in x 4.50 in x 1.77 in / 237 mm x 114.5 mm x 45 mm
Troubleshooting
Problem | Possible Cause | Solution |
---|---|---|
How to properly set the input sensitivity | Please refer to Appendix A to set |
the input sensitivity for maximum, low-distortion output.
The amplifier doesn’t turn on| Faulty fuse| Remove the fuse and check with a
continuity meter. Replace if necessary.
Poor connection integrity| Check”+12V”,”Ground”, and “Remote” leads for
pinched wires; ensure tight connections.
Insufficient “Remote” input| Make sure there is a sufficient +12V supply at
the “Remote” connection; if not a relay may be required.
Intermittent output fluctuates when I tap on it or hit a bump| Poor connection
integrity| Make sure insulation has been properly stripped back at connection
points for a good contact area.
Make sure input connectors are making good contact with input jacks of the
amplifier.
Distorted, attenuated, or popping sound| Faulty speaker connection (Short
Circuit / Over Current Protection)| Inspect speaker wires for possible short-
circuit, either together or shorted to the vehicle’s chassis ground.
Check the nominal load impedance at the amplifier is equal to or greater than
Ch.1 & 2: 2 ohms stereo
Ch.1 & 2:4 ohms bridged
Sub Ch.: 2 ohms
Output shuts off after a while| Overheating condition (Thermal Protection)|
Make sure the amplifier mounting area has adequate space for ventilation and
heat dissipation.
No or low subwoofer output| Remote Bass Control (optional)
is connected and turned down| Adjust RBC-1 or M-RBC-1 accordingly
Appendix A:
Input Sensitivity Level Setting
Following the directions below will allow the installer to adjust the input
sensitivity of each amplifier channel pair in just a few minutes using
equipment commonly available in installation bays.
Necessary Equipment
- Digital AC Voltmeter
- CD or file with a sine-wave test tone recorded at 0 dB reference level in the frequency range to be amplified for that set of channels (50 Hz for subwoofer channels, 1 kHz for a midrange application). Do not use attenuated test tones (-10 dB, -20 dB, etc.).
The Nine-Step Procedure
- Disconnect the speakers from the amplifier’s speaker output connectors (you need only disconnect one speaker wire).
- Turn off all processing (bass/treble, loudness, EQ, etc.) on the source unit, processors (if used), and amplifier. Set the source unit’s fader control to center position and its subwoofer level control to 3/4 of maximum.
- Set both “Input Voltage” switches to “Low” and turn both “Input Sens.” controls all the way down.
- Set the source unit volume to 3/4 of full volume. This will allow for reasonable gain overlap with moderate clipping at full volume.
- Using the Target AC Voltage chart (at right), determine the target voltage for input sensitivity adjustment according to the nominal impedance of the speaker system connected to the amplifier outputs.
- Verify that you have disconnected the speakers before proceeding. Play a track with an appropriate sine wave (within the frequency range to be amplified) at 3/4 source unit volume.
- Connect the AC voltmeter to the speaker output connectors of the amplifier. Make sure you test the voltage at the correct connectors (+ and –).
- Increase the “Input Sens.” control until the target voltage is observed with the voltmeter. Note: If excessive voltage is measured with the control set at minimum (full counterclockwise), change the “Input Voltage” switch set to “High” and re-adjust.
- Once you have adjusted the amplifier to its maximum low-distortion output level, reconnect the speaker(s) and listen to the system. The “Input Sens.” controls can now be adjusted downward if the amplifier requires attenuation to achieve the desired system balance.
Target AC Voltage – MX600/3
Nom.
Impedance| Ch.1 & 2
(Stereo)| Ch.1 & 2
(Bridged)
4Ω| 17.3| 28.3
2Ω| 14.1| not recommended
Nom.
Impedance| Ch.3/Subwoofer
4Ω| 31.6
3Ω| 30
2Ω| 28.3
! IMPORTANT
Do not increase any “Input Sens.” setting for any amplifier channel or channel
pair in the system beyond the maximum level established during this procedure.
Doing so will result in audible distortion and possible speaker damage.
It will be necessary to re-adjust the “Input Sens.” for the affected channels if any equalizer boost is activated after setting the “Input Sens.” with this procedure. This applies to any EQ boost circuit, including source unit tone controls or EQ circuits. EQ cuts will not require re-adjustment.
Appendix B
Remote Bass Control
With the optional RBC-1 or M-RBC-1 Remote Bass Control (each sold separately),
you can control the subwoofer volume from the front of the vehicle/vessel.
The remote’s plug connects to the amplifier’s harness-mounted RJ11 input jack.
When connected to the amplifier, the Remote Bass Control operates as follows.
At full counter-clockwise rotation, the audio will mute completely. At full
clockwise rotation, the level will be the same as if the remote was not
connected at all. In other words, it operates strictly as a subwoofer level
attenuator. This control will not affect the “Bass Boost” feature of the
amplifier. Care should be taken to securely mount this control in a manner
that does not interfere with vehicle/vessel operation. When setting the
amplifier’s input sensitivity, the Remote Bass Control should be unplugged or
at full clockwise rotation
(maximum level).
Limited Warranty – Amplifiers (USA)
JL Audio warrants this product to be free of defects in materials and
workmanship for a period of two (2) years from the original date of purchase.
This warranty is not transferrable and applies only to the original purchaser
from an authorized JL Audio dealer. Should service be necessary under this
warranty for any reason due to manufacturing defect or malfunction, JL Audio
will (at its discretion), repair or replace the defective product with the new
or remanufactured product at no charge. Damage caused by the following is not
covered under warranty: accident, misuse, abuse, product modification or
neglect, failure to follow installation instructions, unauthorized repair
attempts, or misrepresentations by the seller. This warranty does not cover
incidental or consequential damages and does not cover the cost of removing or
reinstalling the unit(s). Cosmetic damage due to accident or normal wear and
tear is not covered under warranty.
The warranty is void if the product’s serial number has been removed or
defaced.
Any applicable implied warranties are limited in duration to the period of the
express warranty as provided herein beginning with the date of the original
purchase at retail, and no warranties, whether express or implied, shall apply
to this product thereafter. Some states do not allow limitations on implied
warranties, therefore these exclusions may not apply to you. This warranty
gives you specific legal rights, and you may also have other rights, which
vary from state to state.
If you need service on your JL AUDIO product:
All warranty returns should be sent to JL Audio’s Amplifier Service Facility
freight-prepaid through an authorized JL Audio dealer and must be accompanied
by proof of purchase (a copy of the original sales receipt). Direct returns
from consumers or non-authorized dealers will be refused unless specifically
authorized by JL Audio with a valid return authorization number.
Warranty expiration on products returned without proof of purchase will be
determined from the manufacturing date code. Coverage may be invalidated as
this date is previous to the purchase date. Non-defective items received will
be returned freight-collect. The customer is responsible for shipping charges
and insurance in sending the product to JL Audio. Freight damage on returns is
not covered under warranty.
For Service Information in the U.S.A. please call JL Audio Customer
Service:
(954) 4 43 -110 0
9:00 AM – 5:30 PM (Eastern Time Zone)
JL Audio, Inc.
10369 North Commerce Pkwy.
Miramar, FL 33025
(Do not send product for repair to this address)
International Warranties:
Products purchased outside the United States of America are covered only by
that country’s distributor and not by JL Audio, Inc.
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