Kicker KXM400.4

4-channel marine amplifier — 50 watts RMS x 4 at 4 ohms

Item #: 2064KXM4K4

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Kicker expertise in a marine amp

The key to building a great marine amp is building a great amp, period. When Kicker designed their KXM line, they used the company's popular Kicker KX car amps as a starting point. Kicker KXM amps combine first-rate technology with water-resistant, protective hardware outside, so they're ready for life on the water.

A better amp designed for boaters

Kicker's KXM400.4 4-channel amplifier can supply 4 speakers with up to 50 watts RMS each, so you'll hear all the beauty and brilliance of your favorite songs over the roar of the wind and water. This reliable and compact amp remains cool even when pushed hard, thanks to its high-mass heatsink, high-tech internal components, and efficient full-range Class-D amp technology.

Building a marine system for your boat and wondering what to buy first? You could use this versatile amp in 2-channel mode to drive a pair of subs with up to 200 watts each, then switch the amp over to power all your speakers when you get a bigger sub amp. Space can be at a premium on some boats, but this amp's compact exterior makes it easier to mount in tight spaces.

Kicker KXM400.4 4-channel marine amp

The RCA inputs on this Kicker amp will accept signal from just about any marine stereo.

Made for marine use

No matter how snug the installation space, marine amps have to be tough enough to stand up to the marine environment. The KXM400.4 features a conformal coated circuit board for improved water and dust resistance, plus corrosion-resistant power connections, a gasket-sealed front cover, and stainless steel mounting hardware that won't rust all over your boat's gel coat or carpeting. The all-weather protection even extends to the UV-protected heat sink finish.

The amp's RCA inputs accept speaker-level or line-level signals, so you can connect this amp to almost any stereo. Kicker even included a 3-second turn-on delay, which eliminates any annoying (and potentially damaging) turn-on pops.

Versatile controls behind the folding door

You can tune for almost any kind of speaker, as the steeply-sloped high- and low-pass filters offer a wide range of adjustment. The filter section for the rear channels can be set up for bandpass operation – where both the high- and low-pass filters are engaged to allow only the frequencies between them to play – for optimizing the signal to midrange drivers or other component speakers. The front and rear channels offer separate bass boosts, giving you more flexibility when you want to add some extra kick to your music.

Product Highlights:

  • 4-channel marine amplifier
  • 50 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
  • 200 watts RMS x 2 bridged at 4 ohms (4-ohm stable in bridged mode)
  • variable bass boost (0-18 dB at 40 Hz)
More info:
  • Class D amp technology for outstanding performace and compact footprint
  • Fail-Safe Integration Technology eliminates noise from your boat's electrical system
  • conformal coated circuit boards for improved water and dust resistance
  • corrosion-resistant power terminals
  • gasket-sealed front cover keeps water out and prevents tampering
  • stainless steel mounting hardware prevents rust stains in carpet and gel coat
  • blue light-pipe illumination matches Kicker's illuminated marine speakers
  • sealed potentiometers for reliability and long life
  • UV-resistant heat sink finish
  • 11-3/16"W x 2-1/8"H x 8-5/16"D
  • warranty: 2 years (extends to 3 years when purchased with a Kicker amp wiring kit)
  • Our 60-day money-back guarantee

Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel marine amplifier
  • 3mm Allen wrench
  • Four 2" Stainless steel self-tapping screws
  • 4 Stainless steel flat washers
  • Owner's manual (English/ Spanish/ German/ French)
  • Kicker "Livin' Loud" power certificate

Product Research



Marine Amplifier: The Kicker KXM400.4 marine amplifier's special weather-resistant features allow it to withstand the harsh marine environment and give you dependable performance. The internal circuit board has been sprayed with a moisture-deterring, protective conformal coating for water and dirt resistance. The power, speaker, and input connections are gasket-sealed, as is the cover hiding the control settings, creating a water-resistant barrier to key components. Stainless steel mounting hardware prevents rust stains, and the UV-treated chassis finish battles harsh sunlight.

Class D Amplifier Design: The full-range Class D amplifier uses digital switching to amplify audio signals, resulting in high efficiency and less heat. The Class D design also allows a small footprint for increased cargo space.

CEA-2006 Compliant: CEA-2006 is a system of testing and measurement methods for mobile audio amplifiers. This voluntary standard advocates a uniform method for measuring an amplifier's RMS power output and signal-to-noise ratio. The criteria for measuring power uses a DC input voltage of 14.4 volts and the RMS power output is measured into a 4Ω load, with 1% or less Total Harmonic Distortion plus noise (THD+N), and over a frequency range of 20 Hz to 20 kHz (for full range amplifiers). Signal-to-Noise ratio is measured in weighted absolute decibels (dBA) at a reference of 1 watt into 4Ω. CEA-2006 allows consumers to compare amplifiers on an equal basis. Using CEA-2006 criteria, the Kicker KXM400.4 is rated at 50 Watts RMS x 4 channels with a 75 dBA signal to noise ratio.

Specifications: The manual also lists these non CEA-2006 compliant specifications:

  • Power:
    • 2Ω: 100 watts x 4 channels (no more than 1% THD+N, 14.4 volts)
    • Bridged: 200 watts x 2 channels (into 4Ω with no more than 1% THD, 14.4 volts)
  • Signal to Noise Ratio: 95 dB (at rated power)

Kicker Livin' Loud Certified Power: The amplifier comes with a certificate that indicates the total maximum RMS power output of the particular amplifier, along with the model number, serial number, and whether the amplifier passed the total harmonic distortion, signal-to-noise ratio, and protection circuit tests.

Protection Circuitry: The KXM400.4 has protection circuitry that will turn the amp off in the event of overheating, over voltage (power input), under voltage (power input), and short circuit (speaker output). If the Protection LED on the front side of the amp illuminates red, the protection circuit has engaged and the amp will not play until the problem is resolved.


Gain: To accommodate the varying range of signal levels coming from today's factory and aftermarket radios, the Kicker KXM400.4 features adjustable gain controls (low level: 125mV-5V, high level: 250mV-10V). The front and rear sections of the amplifier (labeled Amp 1 and Amp 2) have independent rotary gain controls, labeled from 0 to 11.

Input Level Switch: Set the input level switch to Lo when using preamp level input signals and Hi when using speaker level input signals.

Crossover: The front and rear sections of the amplifier have independent crossover circuits:

  • Amp 1:
    • Mode: three position switch; Off (crossover bypassed), HP (high-pass), or LP (low-pass)
    • Range: two position switch; sets the frequency adjustment range for the crossover point dial; 1x (10-500 Hz) or 10x (100-5,000 Hz)
    • Frequency: continuously variable from 10 to 500 Hz (with Range switch in the 1x position) or 100-5,000 Hz (with Range switch in the 10x position)
  • Amp 2:
    • Mode: four position switch; Off (crossover bypassed), HP (high-pass), LP (low-pass), or BP (band-pass, both high-pass and low-pass circuits engaged)
    • Range: two position switch; sets the frequency adjustment range for the low-pass crossover point dial; 1x or 10x
    • High-Pass Frequency: continuously variable from 10 to 500 Hz
    • Low-Pass Frequency: continuously variable from 40 to 500 Hz (with Range switch in the 1x position) or 400-5,000 Hz (with Range switch in the 10x position)

KickEQ: The amplifier's KickEQ bass boost circuits are continuously variable from 0 to +18 dB and centered at 40 Hz. The front and rear amps have separate bass boost controls.

Auto Turn-On: The Auto Turn-On switch offers three options:

  • +12 V: The amp turns on when +12 volts is applied to the remote terminal.
  • DC Offset: The amp turns on when a 6 volt offset is detected on the signal inputs (from a speaker-level source)
  • Audio: The amp turns on when an incoming audio signal is detected

Fader: When your source unit has discrete front and rear outputs, set the fader switch to on. Turn the fader switch off to send a single stereo input to both the front and rear amps.


Power Connections: The power and ground connections are set-screw terminals that will accommodate up to 4-gauge wire. The remote turn-on set-screw terminal will accept up to 8-gauge wire. The included Allen-wrench is required to loosen/tighten the terminals.

Note: The Amplifier is not equipped with an internal fuse. An external 60-amp fuse (not included) must be installed on the power wire. If the system has only this amp and a wiring kit is used that includes a fuse with a value other than 60-amps, the original should be replaced with a 60-amp fuse.

Speaker Outputs: The Kicker KXM400.4 is equipped with four pair of set-screw speaker output terminals. The terminals will accommodate up to 8-gauge wire and are loosened/tightened with the included Allen-wrench.

Dual Sensitivity Inputs: The KXM series amplifiers have dual input sensitivity differential RCA inputs, which will accept either speaker-level (high) or preamp (low) signals from your source unit. A high-level signal can be run from the head unit's speaker outputs to the stereo RCA inputs of the amplifier using Speaker Wire to RCA adapters (206KiSL, sold separately). The Input Level Switch on the amp should be set to high when using a speaker-level input, and low when using a line-level input.

Line Level Output: The amplifier has a pair of RCA line level outputs for feeding another amplifier. This is the same signal that is present at the amp's inputs. Either input method (speaker-level or RCA) will provide a low-level output signal to the RCA outputs. The amplifier's crossovers have no effect on the line level output signal, however, if you input a filtered signal from the head unit, the amp's low-level output will also be filtered.

Our Product Research Team

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