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JL Audio JX400/4D

400W RMS JX Series 4-Channel Class D Full-Range Amplifier

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JL Audio JX400/4D

400W RMS JX Series 4-Channel Class D Full-Range Amplifier

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JL Audio XD-PCS4-1B 4 Gauge Wiring Kit

Get a JL Audio wiring kit to match your new JL amplifier! Don't forget the RCA's!

$119.99

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NVX Universal Remote Level Bass Control

Controls bass level and frequency via RCA/Interconnect connectors on any amp.

$7.99

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Kicker 4-Channel RCA Audio Interconnect Cable

4 Meters (13 ft.) 4-Channel K-Series RCA Audio Interconnect Cable

$19.99

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50% off a True 4 Gauge NVX Amp Kit with Purchase

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NVX XKIT44

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• 4 Gauge 4-Channel X-Series Complete Amplifier Installation Kit
• For Car Audio Systems Up To 1000 Watts RMS
• Silver-Tinned 100% Virgin Copper
• 4-channel RCA Interconnect Cable

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JL Audio JX400/4D

JL Audio JX400/4D - JX Series 4-Channel Class D Full-Range Amplifier

The JL Audio JX Series of amplifiers are designed with a specific purpose; to deliver clean, rock-solid performance and reliability at an affordable price. The JL Audio JX400/4D is a four-channel, full-range audio amplifier utilizing Class D technology that can be operated with a wide variety of source units and system configurations. Unlike gimmicky price-conscious amplifiers, JL Audio employs specified oversized output transistors and rugged MOSFET power supplies to unsure proper current, thermal capacity and better overall performance. In addition, the JX400/4D includes flexible signal processing capabilities with a fully variable 12 dB/octave crossover filter, pass-through preamp outputs and high-level inputs.

Integration Flexibility

Integration Flexibility

For those systems that do not offer a preamp level signal option, you can connect speaker level signals directly to the “Hi-Level Inputs” connector using the supplied connector and wire harness. Simply splice the appropriate left/right and positive/negative wires to the included harness and plug the harness into the “Hi-Level Inputs” connector on the amplifier. The JX monoblock will attenuate the high-level signal to make it compatible with its input stage. Alternatively, a traditional left/ right pair of RCA type jacks is used for preamp level (low-level) signals. This is the preferred connection method whenever available.

Low-Pass Active Filter

Selectable 12 dB / octave filter

The JX class D full-range amplifier features a defeatable 12 dB / octave filter, which can be configured as a low-pass or high-pass filter and offers continuously variable cutoff frequency selection from 50-200 Hz. This feature is designed to attenuate frequencies above or below its filter frequency, so that the system’s speakers do not reproduce any audible and often harmful frequencies. 80 Hz is a good starting point for system tuning, but its also advisable to match the crossover point with that of your subwoofer's low-pass filter - this ensures that your system is properly distributing the frequencies to the appropriate medium.




General Features:

  • JX Series 4-Channel Class D Subwoofer Amplifier
  • RMS Power Rating (14.4V):
    • 4 ohms: 70 watts x 4 chan.
    • 2 ohms: 100 watts x 4 chan.
    • Bridged, 4 ohms: 200 watts x 2 chan.
  • RMS Power Rating (12.5V):
    • 4 ohms: 50 watts x 4 chan.
    • 2 ohms: 80 watts x 4 chan.
    • Bridged, 4 ohms: 160 watts x 2 chan.
  • Unregulated PWM switching type power supply
  • LED power (green) and protect (red) indicators
  • Soft start turn-on prevent clicking and popping when system turns on
  • Speaker-level (high-level) inputs with included harness
  • Preamp RCA outputs to daisy chain multiple amps
  • 3-way protection circuitry (thermal, overload, and speaker short protection)
  • Heavy duty aluminum alloy heatsink for effective heat dissipation
  • Nickel-plated RCA level inputs
  • Nickel-plated screw terminals
  • Selectable input mode: 2 Ch. / 4 Ch.
  • Input sensitivity:
    • Low level input: 200mV - 4V
    • High level input: 2.0mV - 10.0V
  • Selectable filter mode: HP / Off / LP
  • Variable cutoff filter: 50 - 200 Hz, 12 dB/octave
  • Frequency Response: 20 - 20,000 Hz
  • Total Harmonic Distortion (THD): <1%
  • Signal to Noise Ratio: >93 dB
  • Damping Factor @ 4 ohms: >60 @ 4 ohms
  • Fuse Rating: 40A x 1 inline (not supplied)
  • 4 gauge power and ground wiring is recommended for installation. Contact us for information regarding a discount on select amplifier kits from our website when purchased together with this amplifier.
  • Weight: 4.80 lb
  • Dimensions: 7.68"W x 9.05"L x 2.09"H
  • Authorized Internet Dealer
  • 2 Year Manufacturer's Warranty


Check out the JL Audio JX400/4D Owner's Manual

Product History:

JL Audio RD400/4 thumbnail
(newest, current model)
JL Audio JX400/4D thumbnail
(previous model, replaced by JL Audio Class-D 4-Channel RD400/4)
JL Audio JX360/4 thumbnail
(previous model, replaced by JL Audio JX400/4D)

Power Specifications - Full Range Channels

RMS Power @ 4 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 4 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

70 watts x 4 channels
RMS Power @ 2 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 2 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

100 watts x 4 channels
Bridged RMS Power

Bridging refers to combining two channels on an amplifier to create one channel with double the voltage and an increased power output. A 2-channel amplifier will bridge down to 1-channel and a 4-channel amplifier can bridge to create 2-channels. An amplifier is most commonly bridged to drive a subwoofer.

Remember, once you bridge two channels down to one its final impedance will be 4 ohms unless otherwise specified. This rating lists the RMS power created once an amplifier is bridged.

200 watts x 2 channels

Amplifier Specifications

Amplifier Series
This designates the series of the amplifier. Many amps are available in a litany of different wattage and channel configurations, but maintain consistent features throughout the product line.
JX (JL Audio)
Amplifier Class

An amplifier increases the power of the signal being fed to it by taking energy from its power supply and matching the signal but increasing its amplitude. Amplifiers use many different methods for converting these electrical signals and have been categorized into classes.

Class A/B: Greater than 50% of the input signal is amplified while the other percentage is “off”. These amplifiers have a small amount of current flowing through the output transistors all the time which almost eliminates crossover distortion. Class A/B has great sound quality but is not as efficient as class D. These amps are most commonly used to drive speakers.

Class D: Also known as switching amplifiers, class D amps have output transistors that are completely turned “on” or “off”. This means that when the transistors are on, there is almost no voltage across them but when they are off there is significant voltage but no current flowing through it which makes these amplifiers very efficient at the cost of sound quality. These amps are most commonly used to drive subwoofers.

Other Classes: You may see classes such as GH, bD, X, FD, etc. by some manufactures. These amplifiers tend to be either class A/B, D or a hybrid of the two but with improvements to their designs that can make them more efficient or offer better sound quality.

D
Number of Channels
Each channel on an amplifier will power one speaker using a positive and negative cable. There are various types of amplifiers, each designed to power a certain number of speakers. Monoblock amplifiers, also known as single channel, are designed to power one or more subwoofers. These amplifiers often have very high power ratings. On the other hand, multi-channel amplifiers power multiple speakers, usually at lower power ratings. 2-Channel and 4-Channel amplifiers can power car speakers or low powered subwoofers. Occasionally you might see a 5 or 6-channel amplifier that can power speakers and subwoofers at the same time. The most common setup is a monoblock amp to run subwoofers and a 4-channel amp to run door speakers. Check out our Knowledge Base for more information.
4
Total RMS Power Output
Total RMS power is measured by multiplying RMS power per channel by the number of channels, and is calculated at the lowest level of operating impedance.

RMS power is the amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds.

The RMS output figure is much more accurate than the peak rating when comparing products.

400 watts
Maximum Input Gauge Size
This is the largest gauge wire that will fit into the power and ground terminals of this device. The lower the gauge number, the thicker the wire is. For example, a 4 gauge wire is thicker than an 8 gauge wire and thus has higher current carrying capacity. Always do your best to get this size wire to reduce the risk of damage to your components.
4 AWG
Minimum Impedance Unbridged
The lowest impedance the amplifier will handle when it is not bridged.
2 ohms
Minimum Impedance Bridged
The lowest impedance the amplifier will handle when it is bridged.
4 ohms
THD at Rated RMS Power
The amount of change in harmonic content of the signal as it is amplified. A lower figure indicates less change and a more accurate amp. THD below 0.10% is inaudible.
<1%
Speaker Level Inputs
Speaker level inputs are commonly referred to as high-level inputs and vice versa. This input type allows you to get your audio signal directly from the speaker wire in your vehicle, instead of using RCA cables. The advantage of this is factory integration, as most stock radios do not have RCA outputs to run amplifiers.
Yes - with included adapter
Preamp Outputs
Many amplifiers are equipped with RCA preamp outputs which pass the original music signal from the source to additional amplifiers. This is known as daisy chaining because the source connects to the first amp, and the first amp connects to the second amp, etc. The advantage to daisy chaining is you only need one 2-channel RCA cable to transfer the signal from the head-unit to the amplifier, and then one additional cable for each amp being daisy chained.
1 pair
Built-in Crossover

A crossover is a type of filtering system that permits only certain frequencies to play. A Low-Pass (LP) crossover allows only frequencies below its setting to get through which is good in the case of some subwoofers. A High-Pass(HP) filter allows frequencies above its setting to pass through, this is normally used on speakers.

When a crossover is set to FULL it means no filtering is added and the full frequency spectrum is allowed through the amplifier. Filtering is important because feeding a speaker frequencies it cannot reproduce effectively creates distortion.

Low-Pass (LP)
High-Pass (HP)
Full (AP)
High-Pass Crossover Frequency
The high-pass crossover frequency can be a fixed crossover point or a variable crossover range. A variable high-pass crossover allows you to select a specific crossover point which allows frequencies above the set crossover point to pass, while making frequencies below the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

50 - 200 Hz
Low-Pass Crossover Frequency
The low-pass crossover frequency is typically used for subwoofers. It can be a fixed crossover point or a variable crossover range. A variable low-pass crossover allows you to select a specific crossover point which allows frequencies below the set crossover point to pass, while making frequencies above the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

50 - 200 Hz
Signal-to-Noise Ratio
This spec compares the strength of the signal to the level of background noise. A higher value indicates less background noise.
>93 dB
Bass/Gain Remote
If the amp comes with a bass/gain remote you will be able to control the level of your bass from your dashboard. Typically bass remotes also include a 16-20 ft. wire for installation.
No
Strappable
Some amplifiers can be "strapped" together in order to increase the output of a single audio channel. These amplifiers feature RCA preamp outputs, allowing you to pass the signal directly from one amp to the other to ensure consistency.
No
Sonic Certified Amplifier
Sonic Certified amplifiers have been tested by the experts at Sonic Electronix to meet or exceed the wattage ratings provided by the manufacturer. If this is marked as Yes, then you can trust the wattage ratings. If marked as No, then we have tested the amplifier and it did not meet the advertised wattage ratings. If marked as Not Tested, then the Sonic Electronix experts have not yet been able to test the amp.
Not Tested
Hi-Res Audio Compatible
This feature refers to if the product is capable of Hi-Res Audio (HRA) playback.

Specials with this Item

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Warranty and Return Policy

Parts Warranty Duration
2 years
Labor Warranty Duration
2 years
Warranty Provider
Manufacturer

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
100%
4 Star
0%
3 Star
0%
2 Star
0%
1 Star
0%

Average Attribution Rating

Durability
5.0
Value
5.0
Features
5.0
Design
5.0
Usability
5.0
Keith

Brooksville, Fl.

Overall
Durability
Value
Features
Design
Usability
The Best Amp for the money

June 16, 2015

Bought this Amp because my brother has one and I'm familiar with the name and product . I paired it with component JBL speakers and it sounds incredible. Only downside is a little Engine noise that I need to filter out . Amp has a lot of power !

9 of 11 found this helpful

Was this review helpful to you?

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Product Summary

Manufacturer

Model Number

JX400/4D

UPC

699440994019

Weight

5.80lbs

Internal SKU

jx4004d

Internal Product ID

93399

Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: JL Audio JX400/4D