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JL Audio XD300/1

Mono subwoofer amplifier — 300 watts RMS x 1 at 2 ohms

6 Reviews

Item # 136XD3001

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Our take on the JL Audio XD300/1

Each JL Audio XD amp packs a wallop far beyond what you'd expect from something so small. This super-compact amp plays your music with true fidelity and impressive impact, without straining your car's electrical system. A cast alloy heatsink and an advanced cooling system keep these amps at optimal temperature, eliminating thermal shut-downs so your music keeps going strong without interruption.

Each JL Audio XD amp packs a wallop far beyond what you'd expect from something so small. This super-compact amp plays your music with true fidelity and impressive impact, without straining your car's electrical system. A cast alloy heatsink and an advanced cooling system keep these amps at optimal temperature, eliminating thermal shut-downs so your music keeps going strong without interruption.

The XD300/1 mono amp delivers up to 300 watts RMS to your subwoofer system, and its low-pass filter features a choice of slopes for better control over the character of your bass.

"Differential-balanced" inputs keep the signals clear of outside noise, and allow you to connect this amp to just about any in-dash stereo, even a factory radio with no preamp outputs. An optional wired remote lets you tweak the level from your front seat.

Confused about impedance? Check out our article on matching subs and amps.

Product Highlights:

  • mono subwoofer amplifer
  • 200 watts RMS x 1 at 4 ohms (300 watts RMS x 1 at 2 ohms)
  • variable low-pass filter (50-500 Hz, 12 or 24dB/octave)
  • optional wired remote for level control
  • Class D amplifier design with NextD™ switching amp technology
  • differential-balanced inputs eliminate noise coming from your vehicle's electrical system
  • Advanced Rollback Protection System prevents thermal shut-down
  • speaker- and preamp-level inputs (speaker-level input requires an optional adapter)
  • preamp outputs
  • 8-gauge power and ground leads and a 30-amp fuse recommended — wiring and hardware not included with amplifier
  • no onboard fuses — when installing multiple amps in a system, an additional 30-amp in-line fuse between the distribution block and the amplifier is recommended
  • 6-7/8"W x 2"H x 7-1/8"D
  • warranty: 2 years
  • Our 60-day money-back guarantee

Hard hitting compact amp easy to install also easy to hide.

jack, wichita,ks

What's in the Box:

  • Monoblock Class-D subwoofer amplifier
  • Hex-key
  • JL Audio emblem
  • Owner's Manual

JL Audio XD300/1 Reviews

Average Customer Review(s):

(6 Reviews)

Bigger isn't always better

Sean G from Orlando, FL on 5/10/2014

Crutchfield Customer Review (What's this?)

You will not believe how small this amp is when you take it out of the box. It is tiny, powerful, and efficient. I went from an old MTX Thunder 421D to this, with no other system mods, and my 12W6v2 really woke up. I would buy this amp again and again, if I had more systems to build. Highly recommended.



Size doesn't matter

jack from wichita,ks on 5/14/2013

Crutchfield Customer Review (What's this?)

Hard hitting compact amp easy to install also easy to hide.

Pros: size and sound

Cons: none

Great sounding mono amp

Joe from Michigan on 3/7/2013

Best low watt mono amp you will ever hear

Pros: Sound quility

Cons: None

JL Delivers Again

Devon R from Lockbourne, OH on 6/11/2012

With JL, you get what you pay for, and they certainly deliver on this one. The Class D efficiency is fantastic; it's small, it produces no discernible noise, and won't stress the electrical system (stock alternator without upgrading the big 3* in a 1998 Ford Contour). Compared to my old sub-amplifier (which kicked the bucket after running well for 10 years), this amp sounds amazing (driving a single 10" JL Audio 125 W RMS sub in a custom, 4th order bandpass enclosure). It kicks nice, and the lows sound amazing, both in bass heavy, electronic (House, Dubstep, Trance) music, and in hard rock/metal. In fact, it sounds so great that a week later I ran out and bought the XD 400/4 to power my front and rear door speakers. The features are great on this amp. I'm not using the crossover (my head unit already has one), but I tested it out and performs exactly the way it should. Great if you have no sub out on your deck. The input sensitivity setting is amazing. Using my AC Voltmeter and my IASCA test disc, I can set the gain to power my 125 W sub (remember the amp is 200 W) and have no fear whatsoever of overpowering the driver and damaging it. Handy, right? It also has dual +/- speaker connections so you can parallel wire your dual subs at the amp, rather than soldering together wire later; super simple. Aesthetically, it also looks slick, very modern. *For non-car audiophiles: the big 3 is the battery to alternator, alternator to ground, and battery to ground wires.



JL Audio XD300/1

Paul H from Central NJ on 9/10/2011

I was recommended this amp to power a dual 10" JL box by a local dealer. The combo is very clean,tiny is size, extremely punchy, and adds an octave or two to the bottom end in my 2011 LaCrosse. Impressed enough to get one for my business' project Camaro.



JL Audio XD300/1

Scott from Columbus, OH on 4/13/2011

Great product. Highly recommend. Excellent sound quality. Easy to install instructions. Small size makes it easy to hide.




Hands-on research

Product Research



Monoblock Class-D Subwoofer Amplifier: The JL Audio XD300/1 is a monoblock amplifier utilizing JL Audio NexD high-speed switching technology to deliver outstanding fidelity and efficiency. The XD300/1 can be operated with a wide variety of source units and system configurations. Its frequency response is limited to the range below 1 kHz. Every aspect of its operation has been optimized for low-frequency amplification.

Note: The XD300/1 is not designed for driving midrange speakers or tweeters.

Amplifier Rating: The JL Audio XD300/1 Class D monoblock, subwoofer amplifier is rated at 200 Watts RMS x 1 channel at 4-ohms (20 Hz to 20 kHz), Signal-to-Noise Ratio 100 dB, 1% THD, 14.4 Volts. At 2 ohms, the rated power is 300 Watts RMS.

NexD Class D Technology: NexD is a state-of-the-art switching amplifier design that combines exceptional audio quality with excellent efficiency and less complexity. This results in affordable compact amplification with superb sound quality.

Advanced Rollback Protection: The XD-Series amplifiers employ advanced thermal and low-impedance protection to virtually eliminate annoying amplifier shut-down events. Should any XD-Series amplifier ever overheat, its intelligent, unregulated power supply reacts by limiting available peak voltage until the amplifier returns to a safe temperature range. Likewise, if an impedance lower than optimal for the amplifier is present at the outputs, the XD amplifier will roll back peak voltage to protect itself without shutting down.

Differential-Balanced Inputs: The JL Audio amplifier features differential-balanced input architecture to effectively control noise and ensure compatibility with a wide variety of source units, including many OEM systems. Without resorting to line output converters, you can directly connect most OEM source units to the JL Audio amplifier without creating any noise or compatibility issues. Unlike conventional single-ended inputs, the differential-balanced design does not connect one side of the audio signal to chassis ground. This eliminates any voltage sensitivity between one input terminal and ground and greatly reduces the incidence of alternator whine in a typical car audio installation.

Note: You will need a speaker wire to RCA adaptor (136XDCLR2S, sold separately) to connect this amplifier to your headunit via speaker-level.

Protection Circuitry With Status Indicator Lights: There is a single multi-color LED on the top panel of the amplifier to indicate the amplifier's operating status.

  • Flashing Green: When the LED is flashing green, the amplifier is powering up and audio output is muted.
  • Constant Green: This LED lights green to indicate that the amplifier is turned on and operating normally.
  • Constant Red: This Red LED lights to indicate that the amplifier has exceeded its safe operating temperature, putting the amplifier into a self-protection mode, which reduces the power output of the amplifier. The red light will shut off and the amplifier will return to normal, full-power operating mode if the heat sink temperature drops back to a safe level.
  • Constant Amber (Yellow): The Amber (Yellow) LED light indicates that an over-current condition has occurred and is accompanied by a muting of the amplifier's output. Over-current condition can be caused by a speaker impedance lower than the optimum load impedance range for the amplifier or a short-circuit in the speaker wiring.
  • LED Off: The only condition that will shut down an undamaged XD300/1 completely is if battery voltage or remote turn-on voltage drops below 10-volts. The amplifier will turn back on when voltage climbs back above 11-volts.

Cooling System: The outer shell of the JL Audio amplifier is designed to remove heat from the amplifier circuitry. For optimum cooling performance, this outer shell should be exposed to as large a volume of air as possible.  Enclosing the amplifier in a small, poorly ventilated chamber can lead to excessive heat build-up and degraded performance.


Control Panel Cover: The XD300/1 features a Control Panel Security Cover which protects and hides the amplifier's controls. When installed, the cover ensures that the amplifier's settings are not accidentally changed while creating a clean aesthetic look for the amplifier and your installation. The control panel security cover is pre-installed at the factory and must be temporarily removed to access the amplifier's controls. The security cover is secured by two 2.5mm hex-head screws.

Simplified Gain Setting: The XD Series amplifier makes setting the gain level of the amp via the input sensitivity control very simple. All you need is Digital AC Voltmeter (142TK12V, sold separately) and a Test CD Disc (503CD104, sold separately) 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).

Flexible Input Section And Active Crossover Network: The JL Audio XD amplifier provides a flexible input section and a comprehensive crossover network to fine tune your system effectively and accurately. The variable filter design employed in the JL Audio XD amplifier crossover sections allow you to seamlessly switch slopes, easily change filter frequencies and address what frequencies the preamp inputs will pass. The XD300/1 offers the following independent crossover adjustments behind a removal cover plate:

  • Switchable Slope on Low-pass filter: 12dB/octave Butterworth or 24dB/octave Linkwitz-Riley alignments allowing for more precise integration of subwoofer and speaker channels.
  • Variable Frequency: Fully-variable frequency selection from 50-500 Hz for low-pass crossover.

Note: The amplifier's low-pass filter can be bypassed in order to use an external active crossover in your car audio system. With the internal crossover turned off, the XD300/1's upper frequency response is limited to 1 kHz.


Power/Ground/Turn-On Terminals: This JL Audio XD amplifier features screw clamp terminals for the power, ground, and remote turn-on connections. A 2.5mm hex-wrench is supplied for tightening or loosening the set screws.

  • Power and Ground: The amplifier's screw clamp Power and Ground connections are designed to accept 8 to 4 AWG power wire.
  • Remote Turn-On: The amplifier's screw clamp turn-on lead will accept 18 to 8 AWG wire.

Note: The Amplifier is not equipped with a fuse. An external 30-amp AFS, AGU, or MAXI fuse must be installed on the power wire. If a wiring kit is used which includes a fuse with a value other than 30-amps, the original should be replaced with a 30-amp fuse

Speaker Output Terminals: The JL Audio XD300/1 features four screw clamp speaker terminals for an easy parallel subwoofer connection. The XD300/1 amplifier's four set-screw speaker terminals will accept 16 to 8 AWG speaker wire.

Preamp Inputs: The amplifier features one set of differential-balanced RCA jack inputs. The amplifier features a dedicated Input Sensitivity gain control for these inputs. These controls are designed to match the input sensitivity of the XD300/1 to the specific signal source that is feeding it. The amplifier's input level can be set between 100mV-4V RMS.

Preamp Outputs: The XD300/1 incorporates a pass-through preamp output sections, so that additional amplifiers can easily be connected to the same signal feeding the XD300/1. These preamp output signals are buffered to prevent noise and are always preamp level, regardless of the level of signals feeding the XD300/1's inputs.

Remote Level Control: The amplifier features a standard RJ-14 telephone connector for adding an optional wired remote level control. With the addition of the optional wired Remote Level Control (136HDRLC, sold separately), you can control the volume of the XD300/1 from the driver's seat. If desired, multiple XD amplifiers can be controlled from a single HD-RLC controller using a simple phone line splitter and multiple phone cables.

Note: All inputs and outputs are located on the front side of the amplifier to make installation of the amplifier simple and neat.

Our Product Research Team

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