Contact us
Close contact box

JL Audio JX400/4D

4-channel car amplifier — 70 watts RMS x 4

Item # 13699401

JL Audio's JX400/4D 4-channel amplifier delivers 70 watts RMS to each of your car's front and rear speakers so...

Read more from Crutchfield writer, Buck P.

Ships free today

In Stock
$219.99

Other options

About the JL Audio JX400/4D

Power your music

JL Audio's JX400/4D 4-channel amplifier delivers 70 watts RMS to each of your car's front and rear speakers so you'll hear and feel your music clearly over the noises of the wind and road. You can also switch over to 2-channel mode, and power a pair of subwoofers with 200 watts RMS each, and fill your ride with bass.

Power your music

JL Audio's JX400/4D 4-channel amplifier delivers 70 watts RMS to each of your car's front and rear speakers so you'll hear and feel your music clearly over the noises of the wind and road. You can also switch over to 2-channel mode, and power a pair of subwoofers with 200 watts RMS each, and fill your ride with bass.

Convenient features

JL Audio JX400/4D

Variable high- and low-pass filters allow you to tune the amplifier to match your particular speaker or subwoofer system. The amp includes speaker-level inputs, along with preamp inputs and outputs, so it's ready to work in virtually any system.

Rugged construction

JL Audio designed this hefty little amplifier with sturdy, high-grade parts that ensure excellent heat management, provide high current flow, and deliver stable performance in almost any situation. Inside, you'll find oversized output transistors and a rugged MOSFET power supply; outside, the sleek, high-mass aluminum heatsink keeps things cool enough to virtually eliminate thermal shut-downs.

JL Audio JX400/4D

JX400/4D input and control panel

READ LESS

Product highlights:

  • 4-channel car amplifier
  • 70 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
  • 200 watts RMS x 2 at 4 ohms
  • Class D amplifier design
  • frequency response: 20-20K Hz
  • variable high- and low-pass filter (50-200 Hz, 12 dB/octave)
  • preamp inputs and outputs
  • speaker-level inputs
  • wiring, fuse, and hardware not included with amplifier
    • 4-gauge power and ground leads and a 40-amp fuse recommended
  • 9"W x 2-3/16"H x 7-11/16"D
  • warranty: 2 years
  • Our 60-day money-back guarantee
  • MFR # 99401
KEEP READINGREAD LESS

What's in the box:

  • 4-Channel amplifier
  • Two 10" speaker-level harnesses
  • 2.5mm Allen wrench
  • 4 Self-tapping screws (3/4" length)
  • 4 Flat washers
  • Owner's Manual

Customer reviews

Loading reviews...

JL Audio JX400/4D Reviews

Average Customer Review(s):

Verified customer (What's this?)
Verified employee purchase (What's this?)

Pros:

Cons:

Crutchfield response

Product Research

Features
Controls
Connections

Features

Four-Channel Class D Amplifier: The JL Audio JX400/4D is a four-channel, full-range amplifier utilizing Class D technology. The JX400/4D can be operated with a wide variety of source units (aftermarket or factory) and system configurations (4-channel, 3-channel, or 2-channel).

MOSFET Switching Power Supply: The amplifier employs a rugged MOSFET power supply for outstanding reliability and operational stability.

Amplifier Ratings:

  • Rated Continuous (RMS) Power @ 14.4V:
    • 70 watts x 4 channels at 4Ω
    • 100 watts x 4 channels at 2Ω
    • 200 watts x 2 channels at 4Ω bridged
  • Rated Continuous (RMS) Power @ 12.5V:
    • 50 watts x 4 channels at 4Ω
    • 80 watts x 4 channels at 2Ω
    • 160 watts x 2 channels at 4Ω bridged

Protection Circuitry: The JX400/4D's protection circuitry automatically shuts the amplifier down if thermal limits are exceeded, a short-circuit is detected in the speaker wiring, or if a dangerously low impedance is connected to the amplifier. Once the problem is corrected, the amplifier will return to normal operation.

Status Indicator Lights: There are two status indicator lights on the right side of the amplifier.

  • Power (Green): This LED lights green to indicate that the amplifier is turned on and operating normally.
  • Protect (Red): The Protection LED lights Red to indicate the amplifier's protection circuitry has been activated.

Controls

Input Sensitivity: The four-channel amplifier's Input Sensitivity Control is used to match your source unit's output voltage to the input stage of the amplifier for maximum clean output.

  • Low-Level Input Range: 200mV-4V (RMS)
  • High-Level Input Range: 2V-10V (RMS)

Input Mode: You can send four discrete channels of input into the amplifier, or feed all four channels with only two channels of input. The Input Mode switch has two positions: 4 Ch. for discrete 4 channels of input or 2 Ch. for feeding four channels with the inputs to Channels 1 & 2.

Variable Crossovers: The JX400/4D has a defeatable 12dB/octave filter for each channel bank. The crossovers can be configured as a low-pass or high-pass filter with a continuously variable cutoff frequency from 50 to 200 Hz.

  • Filter Mode: The amplifier has independent 3-way switches that allow you to select either a Low Pass (LP), High Pass (HP) or Full-Range operation (Off) for Channels 1&2 and Channels 3&4.
  • Filter Frequency: Separate rotary dials let you set the cutoff frequency between 50 to 200 Hz for each channel bank.

Connections

Power/Ground/Turn-On Terminals: The JX400/4D features set-screw terminals for the power, ground, and remote turn-on connections:

  • Power and Ground: The set-screw Power and Ground connections are designed to accept up to 4 AWG wire. A 2.5mm Allen wrench is supplied for tightening/loosening connections.
  • Remote Turn-On: The set-screw turn-on lead will accept 18 to 10 AWG wire. The same 2.5mm Allen wrench is supplied for making the connection.
Note: The Amplifier is not equipped with a fuse. An external 40-amp fuse (not included) must be installed on the power wire within 18" of the positive battery post. If a wiring kit is used which includes a fuse with a value other than 40-amps, the original should be replaced with a 40-amp fuse.

Speaker Output Terminals: The JX400/4D amplifier's eight set-screw speaker terminals will accept 16 to 8 AWG speaker wire. The amplifier's speaker terminals can be wired in a four-channel or bridged two-channel configuration. The 2.5mm Allen wrench is supplied for making connections.

Preamp Inputs: The amplifier features two sets of stereo RCA input jacks. The amplifier features a dedicated Input Sensitivity gain control for each pair of inputs. These controls are designed to match the input sensitivity of the JX400/4D to the specific signal source that is feeding it. The amplifier's low-level input can be set between 200mV-4V RMS.

Speaker Level Inputs: The JL Audio JX400/4D also accepts speaker level signals, including those from factory systems (without the need for a line-output converter), via the supplied supplied speaker-level harness. The head unit's speaker wires should be spliced to the speaker-level harness. The amplifier's high-level input can be set between 2V-10V RMS.

Preamp Outputs: The JX400/4D incorporates a pass-through preamp output sections, so that additional amplifiers can easily be connected to the same signal(s) feeding the amplifier. These preamp output signals are buffered to prevent noise and are always preamp level, regardless of the level of signals feeding the amplifier's inputs.

Loading accessories...

Customer Q&A

Q
Crutchfield asked: Why did you buy this?
A
I am very interested in high quality sound [ Demond  Mar 13, 2019 ]
A
I chose this amp to power 2 pairs of Infinity 6-1/2s with a RMS rating of 55W each. This amp was the best bang for the buck within the range I was looking for. Cant go wrong with a JLAudio product for $200 and a great review rating. [ Hosh85  Feb 16, 2019 ]
A
Clarity [ Anushh  Feb 12, 2019 ]
A
Because they're the best [ Larry  Jan 16, 2019 ]
A
because your advisor recommended it [ Elliott  Jan 06, 2019 ]
A
Recommended by sales rep. [ Alvin  Dec 12, 2018 ]
A
Crutchfield tech Bernie assisted with purchase and did an outstanding job [ Tristan  Nov 27, 2018 ]
A
I have the jl systems for my can am spyder [ Calvin  Oct 07, 2018 ]
A
Great price. [ MAURICE  Sep 25, 2018 ]
A
JL Audio is known for high quality. Drew from Crutchfield explained about the signal to noise ratio and that it would be clean and not to exceed my power ratings on the speakers. After searching and researching it was relief to hear sound advice from experts that know what they are talking about. I would rather buy from Crutchfield than anywhere else because of the exceptional return policy and technical support. [ Srinath  Sep 15, 2018 ]
A
JL Audio quality that fits my budget. Prefer the full sound from using fronts and rears. [ ANTONIO  Jul 26, 2018 ]
A
On Sale & the expand-ability & JL Audio [ S  Jul 05, 2018 ]
A
Prior experience [ Aaron  Jun 04, 2018 ]
A
Enough power, great brand and an awesome deal. [ Eduardo  Jun 01, 2018 ]
A
Nice quality amplifier for the money! [ John  May 23, 2018 ]
A
top rated [ ALAN  Apr 18, 2018 ]
A
replacing my mach system in my mustang and needed a 4 channel amp [ Donald Scott  Feb 15, 2018 ]
A
I read the reviews and I also talked to Hogan about this amplifier so that's why I went with it [ Erik  Jan 05, 2018 ]
A
Nice [ Chris  Dec 22, 2017 ]
A
Otis [ Scott  Sep 21, 2017 ]
A
Price and quality. [ Pete  Sep 01, 2017 ]
A
Great amp. [ DEWAYNE  Aug 23, 2017 ]
A
To replace discontinued JL 320 [ David  Aug 15, 2017 ]
A
I currently have a JL Audio Mono block that I use for my subs. I felt that this amp would be a great compliment to the mono block. [ ROBERT  Jun 27, 2017 ]
A
Dolly [ Peter  Jun 14, 2017 ]
A
Dexter made the recommendation and said it would be a good fit for my other components. The amp seems to have good specs and is reasonably priced. [ Kemper  Jun 07, 2017 ]
A
I've heard nothing but great reviews about this product. Besides JL rocks! [ K  Jun 01, 2017 ]
A
Cj at tech support !!! [ John  May 10, 2017 ]
A
Love jl [ Steven Frederic  May 06, 2017 ]
A
To add clarity to the JL Audio 6x9 and component speakers I purchased. Should be rockin'! [ William  Apr 19, 2017 ]
A
Positive product reviews and recommended by a friend [ Kevin  Feb 18, 2017 ]
A
Good power to money ratio. Needed an inexpensive 4 ch. amp. [ AMAURY  Feb 01, 2017 ]
A
because of there reputation of good audio,I was not disappointed,this amp does as advertised,maybe more [ paul  Jan 14, 2017 ]
A
Great amp excellent size [ Squire C.  Nov 28, 2016 ]
A
Great addition to my system and at a great price [ Steven  Oct 05, 2016 ]
A
Great deal to drive my seperates! [ Kurt  Aug 22, 2016 ]
A
I have had amazing experiences with jl audio. Best sound for the money in my opinion [ Tristan  Jul 25, 2016 ]
A
Good performance reveiws and great price [ PHILLIP  Jul 13, 2016 ]
A
High-quality unit, for best sound at the price. [ D  Jun 25, 2016 ]
A
brand [ Michael  May 13, 2016 ]
A
Great brand and good power for the price! [ LUCAS  Mar 06, 2016 ]
A
High quality brand and warranty, best option [ Dustin  Feb 25, 2016 ]
SHOW MORESHOW LESS

7 questions already asked

Q
can this amp power my JBL Club 6520 (front door) and JBL Club 5000C (Rear Door) safely since they are 3 ohm speakers?
[ Daniel  Mar 12, 2017 ]
1 answer
A
Thanks for your question. For information on selecting the best amp I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system.
[ Kenny  Mar 14, 2017 ]  Staff
Q
Why is the output voltage at each channel so different , ( starting from channel 1 going back to channel 4 ) V16.43 , 15.03, 16.43, 12.72?? That's playing at peak level for clipping. Both adjustments are set to the exact same, 16.43 is what I should be seeing...
[ Squire C.  Dec 07, 2016 ]
1 answer
A
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/.
[ Jeff  Dec 13, 2016 ]  Staff
Q
Also, how does one go about stripping 4 gauge wire?
[ The_Twon7  Jul 10, 2016 ]
5 answers
A
A single edge razor blade or a good sharp pocketknife!
[ Jay  Jul 12, 2016 ]
A
Find out the appropriate strip-back by lining up the wire to the terminal and make a line with a sharpie or score the wire. Then, use wire strippers or shears to lightly score the outer coating. Afterwards, pry and twist with your hand to remove the score. It should not take must force, and if it does score the wire more. Very simple process that has a small learning curve. Good luck.
[ SANDRA  Jul 11, 2016 ]
A
To be honest I use a razor blade and roll it through the sheathing being careful not to cut the copper strands.
[ ryan  Jul 11, 2016 ]
A
I just used a new razor blade and stripped the wire by cutting around the plastic/rubber shielding and used pliers to separate the plastic/rubber shielding off the end.
[ Derek  Jul 11, 2016 ]
A
Carefully
[ Mason  Jul 11, 2016 ]
Q
Can I use mini ANL 40 A fuse for the power wire?
[ The_Twon7  Jul 10, 2016 ]
3 answers
A
Yes you can. I actually used a circuit breaker in mine. You can use a mini fuse though as long as the wire gauge will feed into the holder
[ Richard  Aug 24, 2016 ]
A
A 40 amp fuse would be the recommended size Jl audio states in the owner's manual for that model amp. It doesn't matter if it's a mini ANL fuse or a AGU fuse.
[ JOHN  Jul 11, 2016 ]
A
you "can" use any wire you want. However, the wire holder fits up to a 2 gauge cable. Smaller cable will limit how much power your amp will be able to output.
[ Charles  Jul 11, 2016 ]
Q
Will this Amp fit in a Harley Davidson Street Glide Batwing fairing?
[ Justin  Feb 11, 2016 ]
3 answers
A
May be yes .. this is a very small foot print 4 channel amp available. Sounds good too. I have it on my Toyota Highlander 2015
[ Ramaswamy Reddy Pappula  Feb 12, 2016 ]
A
dunno. its relatively compact, but we talkin full size models. look into models known for being compact before you drop your paycheck. and i dont even know what a fairy batwing hd glider is, dude.
[ CAROL  Feb 12, 2016 ]
A
I am no authority on bikes, but, I believe this would be a bit of a stretch for that application.
[ Jay  Feb 12, 2016 ]
Q
Can this amp successfully power the Focal R-165s2 pair and a JL 10W0v3-4?
[ Jayson  Jun 02, 2015 ]
4 answers
A
Yes it should be perfect if you run the sub bridged off the rear channel and the focals off the front two channels. Hope this helps.
[ EARL A  Jun 04, 2015 ]
A
It should work fine... it's gonna be 70W per channel for the speakers and 200W for the Subwoofer.
[ IVAN  Jun 03, 2015 ]
A
This is the best amp for you & jl audio sub and focal sp
[ ANTONIO  Jun 03, 2015 ]
A
The speakers for sure. My sub is v2 not v3-4 so I'm not 100 percent sure.
[ Zach  Jun 03, 2015 ]
Q
Would this amp be able to power my sub and front speakers?
[ Zach  May 27, 2015 ]
1 answer
A
Thanks for your question. For information on selecting the best amp for your subs I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system.
[ Krissy  May 28, 2015 ]  Staff
SHOW MORESHOW LESS

Loading articles...

TOP