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JBL MS-A1004 100 Watt x 4-Channel Amplifier

4.4 out of 5 stars 6 customer reviews

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Standard Packaging

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  • Four-channel power amplifier--100 watts x 4 @ 4 ohms; 100 watts x 4 @ 2 ohms; bridgeable 200 watts x 2 @ 4 ohms
  • RCA to bare-wire adapters work with all line-level and speaker-level inputs, with switch and Hi2 setting
  • Graphical set-up/status displays for both channel pairs with crossover types, frequency readout
  • Digital input mixer allows any input signal to be routed to any speaker output
  • Digital signal processing for precise control of all input mixer, electronic crossover, and output levels

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Product Features

Product Packaging: Standard Packaging
  • Size (LWH): 13.75 inches, 10.6 inches, 4.8 inches
  • Weight: 5.51 pounds
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Product Description

Product Packaging: Standard Packaging

Product Description

400W True RMS, 4-Channel MS Class D Amplifier w/ Digital Input Mixer and Graphical Status Display

Unprecedented Design and Flexibility

There's nothing wrong with your car audio system that real power can't fix. The JBL MS-A1004 is a compact 4-channel amplifier that gives you up to 400 watts of raw power to use any way you see fit. It connects to any line-level or speaker-level output, and features onboard displays for easy, foolproof installation and configuration. A digital input mixer lets you map your inputs to any speaker outputs, and sophisticated network circuitry puts you in precise control of the crossover points and slopes of each channel pair. With great power comes great possibilities--not to mention great sound--and the MS-A1004 delivers on all counts.

JBL Brand
For more than 60 years, JBL has been delivering world-class listening experiences wherever great sound matters.

Why JBL Sound?

We didn't invent car audio, but we did reinvent the way you upgrade your car audio system. When Hollywood made a long-term commitment to cinema sound in 1927 with the film The Jazz Singer, JBL sound was there. When Jimi Hendrix electrified the stage at Woodstock in 1969, JBL sound was there. For more than 60 years, JBL products have been bringing home the impact and excitement of the world's best recording studios, movie theaters, and concert venues. For years, JBL engineers have been creating these world-class listening experiences in the car. Thanks to advanced technology developed in the professional arena, JBL mobile products simply sound better than the competitions'. High output, easy setup and complete connectivity are all things you can expect from any amplifier that wears the JBL badge. And now JBL engineers have completely revolutionized amplifiers with the incredibly flexible MS amplifiers.

The MS-A1004's sleek, slim design allows it to be installed nearly anywhere.

Improve the Sound of Your System

Good, clean power is the key to making any speaker sound its best, and the new JBL MS-A1004 4-channel amplifier delivers. At 100 watts X 4 (2 ohms or 4 ohms), the MS-A1004 will improve the fidelity of your speakers by giving them all the clean power they need. The MS-A1004 can even be bridged down to two channels to put out 200 watts X 2 into 2 ohms for systems in which high power is needed. And it does this all in a footprint small enough to tuck away nearly anywhere.

Flexible Connectivity

JBL engineers have designed the MS-A1004 to offer flexible connectivity no matter how you plan to build the amplifier into your system.

High-Quality Speaker Outputs

The MS-A1004 features high-quality speaker outputs that offer the use of up to 10AWG wire. This ensures minimal power loss for the most output and sound possible going to your speakers.

The MS-A1004 is easy to install and maximizes performance with high-quality connections.

A unique graphical display makes setup and optimization simple.

The optional wireless bass control makes adjusting bass on the fly easy and is easy to install.

Connects to Any Analog Signal

To make installation into nearly any system a breeze, the MS-A1004 comes with RCA to bare-wire adapters that work with all line-level and speaker-level inputs. This means installation is easy and performance is maximized with no drop in signal. A simple switch allows you to match the input to the signal type, and with the Hi2 setting, it can even be used in conjunction with a factory amplifier. And since the MS-A1004 has a digital input mixer that allows any input signal to be routed to any speaker output, installation is simplified even further. We've made it easy.

Pass-Through Audio Outputs

Building the system of your dreams? The pass-through audio outputs on the MS-A1004 allow you to use multiple amplifiers with a signal source, including the matching MS-A5001 mono subwoofer amplifier.

Graphical Setup and Status Display

Unlike the typical car amplifier, the MS-A1004 uses graphical display on the top of the amplifier for system setup, tweaking, and operational status. This display simplifies setup by using icons for the crossover types, along with a readout of the crossover frequencies by channel. An easy-to-use rotary control lets you dial in the setup precisely. Plus the sophisticated design makes the amplifier look great.

Advanced Circuitry

Sophisticated Crossover Functionality

The MS-A1004 offers unprecedented crossover control and functionality. Outputs can be set to low-pass, high-pass, or even band-pass filtered. And with 97 different crossover points from 20Hz to 20kHz, along with selectable slopes (6dB, 12dB, or 24dB), you can precisely tune your amplifier for any subwoofer you may use.

Digital Signal Processing

At the heart of the MS-A1004 is advanced digital signal processing, which controls the input mixer, electronic crossovers, and all output-level functions. Paired with precise user-selectable band filters, crossover points, and crossover slopes, the DSP optimizes sound quality for the speakers you happen to be using. In fact, the MS-A1004 even comes with an input-level CD to make precise tuning and optimization a snap. Getting the best sound out of your system couldn't be easier.

Complete Control

Wireless Bass Control Compatibility

If you really want to fine-tune your system on the fly, the MS-A1004 is compatible with the JBL MS-WBC wireless bass control knob (sold separately). It gives you control of your bass from the driver's seat without having to run any additional wires.


  • 4-channel amplifier--100 watts X 4 (2 ohms or 4 ohms)
  • Bridgeable to two channels--200 watts X 2 (2 ohms)
  • Low-level and high-level inputs with RCA adapters
  • Speaker outputs with 10AWG compatibility
  • Selectable high- and low-pass filters--(20Hz-20kHz; 6dB, 12dB, or 24 dB/octave)
  • Digital signal processing --Precise, user-selectable band filters, crossover points, and slopes.
  • CD for system setup
  • Graphical user interface for setup and status
  • Compatible with the JBL MS-WBC wireless bass control knob (sold separately)
  • Sleek, slim design fits nearly anywhere

What's in the Box

JBL MS-A1004 DSP amplifier

Build your System


The JBL MS-8 digital processor will automatically equalize and optimize any vehicle's performance in about ten minutes flat by maximizing frequency response, bass performance, dynamics, clarity, detail, and stereo imaging

JBL MS-A5001

The JBL MS-A5001 subwoofer amplifier delivers all the flexibility of the MS-A1004 with the power you need to really get your bass thumping.


The optional JBL MS-WBC wireless bass control will give you complete control of your bass without the hassle and expense of running wires.

Product Information

Product Packaging:Standard Packaging
Product Dimensions 13.8 x 10.6 x 4.8 inches
Item Weight 5.5 pounds
Shipping Weight 8.1 pounds
Item model number MS-A1004
Customer Reviews
4.4 out of 5 stars 6 customer reviews

4.4 out of 5 stars
Best Sellers Rank #719 in Electronics > Car Electronics > Car Audio > Amplifiers > Multichannel Amplifiers
Discontinued by manufacturer Yes

Warranty & Support

Product Warranty: For warranty information about this product, please click here


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Customer Questions & Answers

Customer Reviews

Top Customer Reviews

Package Type: Standard Packaging Verified Purchase
This amp is OK, but I was expecting more. I bought it to replace a 10 year old JBL 35 watt by 4 channel amp. Honestly, the new amp with more than 4 times the claimed power doesn't perform much better than the old one. It also doesn't turn on about 25% of the time without turning off the head unit and then turning it back on. I have the sensing wire hooked up also, so it isn't a line signal sensing issue due to a low volume setting. I do like the built in crossover and easy set up.
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Package Type: Standard Packaging Verified Purchase
Great sounding amp, easy easy easy to setup, and change settings with menu buttons.
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Package Type: Standard Packaging Verified Purchase
Small size, plenty of power.

I would have gave it 5 stars in not for one reason: The powers sensing Turn on/off does not work very well. My amp would cut on and off constantly due to not sensing a signal from a Clarion HU that is on low volume.

You will need to hook up the blue amp on sensing wire just like in the old days.
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