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Build your car audio system on a firm foundation of power — Kenwood power! Kenwood amplifiers are famous for their rugged, no-nonsense reliability and superior sound quality. Their efficient MOSFET power supplies and beefy internal components provide an abundant source of clean, crisp sound at a great dollar-to-watt value.

The KAC-8402 4-channel amplifier is a great way to improve the fidelity of the full-range speakers in your system — you'll hear all the details in your music, whether it's the slide of a finger on an acoustic guitar, or the subtle tones of your favorite singer's voice. Looking for some bass? Put the KAC-8402 into your system to power up a couple of subs with 180 watts of power each!

No matter how you use it, you can choose the frequencies that your speakers receive with the variable high- and low-pass filters. A 6 dB bass boost is available on channels 3 and 4. The KAC-8402 includes speaker-level inputs, for hook-up to your factory stereo. If you're adding multiple amps, you'll appreciate the preamp outputs that allow you to daisy-chain additional amps to this one.

Product Highlights:

  • 4-channel car amplifier
  • 60 watts RMS x 4 at 4 ohms (90 watts x 4 at 2 ohms)
  • 180 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)
  • front channel high-pass filters (50-200 Hz at 12 dB per octave), rear channel high- and low-pass filters (50-200 Hz with 12 dB/octave high-pass and 18 dB/octave low pass)
  • bass boost (6 dB at 90 Hz), channels 3 and 4
  • MOSFET power supply
  • CEA-2006 compliant
  • Tri-way capable (Tri-Way crossover required)
  • preamp- and speaker-level inputs
  • preamp outputs
  • requires 8-gauge power and ground leads — wiring and hardware not included with amplifier
  • fuse rating: 40A x 1
  • 15"W x 2-7/16"H x 11-5/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Hands-on research

What's in the box?

Download owner's manual

  • Four-channel amplifier with 40-amp blade fuse inserted into the chassis
  • Allen wrench
  • Speaker level input harness
  • Rubber terminal cover
  • Four 3/4" Self-tapping screws
  • Instruction Manual (English/French/Spanish)
  • Warranty information
  • Note about rear side cover

Product Research

Inputs and Outputs
Additional Specifications


Multi Channel: The KAC-8402 is a 4-channel amplifier, essentially two stereo amplifiers (referred to as Amp A and Amp B) in one chassis.

Line Level Inputs: Amplifiers A and B each have separate line-level RCA inputs with independent gain (Input Sensitivity) controls. The Input Sensitivity controls will accept an input signal of 200mV to 5.0 Volts. If you are using a receiver with only one pair of preamp outputs, a switch allows you to feed both Amp A and B with a single stereo input. When the amplifier switch is in the A input only position, the fader control on the radio will not allow fading between Amplifiers A and B.

Speaker Level Input: The KAC-8402 comes with a 4-channel speaker level input harness. Once you splice the front and rear speaker wires from the receiver to the harness, you have plug-in convenience to the amplifier. This feature makes it easier to add an amplifier to a factory radio or a receiver with no preamp outputs. The maximum power output from the source receiver can be no more than 40 watts.

Line Level Output: The amplifier has a line level output for feeding a full-range signal to another amplifier. The output is always stereo regardless of the position of the Operation (stereo/mono) switch.

Crossovers: The KAC-8402 has built-in crossovers for both the A and B sections. Amplifier A's crossover is high pass at 12 dB/octave and is continuously variable from 50Hz to 200Hz. Amplifier B's crossover can be set to high pass or low pass. The high pass option, like Amplifier A, is 12 dB/octave and is continuously variable from 50Hz to 200Hz. The low pass option is also continuously variable from 50Hz to 200Hz but has an 18 dB/octave slope.

Bass Boost: A fixed bass boost of 6dB at 90Hz can be engaged for Amplifier B only. There is no bass boost for Amplifier A.

Stereo/Mono Operation: You can independently switch Amplifier A and Amplifier B from Stereo to Mono operation. When switched to Mono, the signal from the left channel input only is used.

Protection circuitry: The amplifier features protection circuits that will shut the amp down in case of the following events:

  • Speaker output contacts ground
  • Speaker wire short-circuits
  • Unit malfunctions and DC is sent to speaker output
  • Internal temperature is too high
  • Loss of ground of head unit or amp

Inputs and Outputs

Front of the Amplifier

  • Fuse: 40 amp
  • BATT (Power): Screw terminal (0.55" wide)
  • GND (Ground): Screw terminal (0.55" wide)
  • P.CON (remote turn-on): Screw terminal (0.33" wide)
  • Speaker outputs: Screw terminals (0.33" wide)
  • GND: Phillips-head screw for RCA signal ground
  • Speaker-level input: Multi-pin input for use with included speaker level input harness
  • A and B line-in jacks: Two pair of RCA inputs
  • Line out jacks: One pair RCA outputs that provide a summed signal from the "A" and "B" sets of line inputs


Top of the Amplifier

  • Input Selector: A/A&B
  • Amp A Crossover: High Pass/Off
  • Amp A Operation Mode: Stereo/Mono
  • Amp A High Pass Frequency: 50-200 Hz
  • Amp A Input Sensitivity: 200 mV-5 V
  • Amp B Crossover: High Pass/Low Pass/Off
  • Amp B Operation Mode: Stereo/Mono
  • Bass Boost (Amp B only): On/Off
  • Amp B High Pass Frequency: 50-200 Hz
  • Amp B Low Pass Frequency: 50-200 Hz
  • Amp B Input Sensitivity: 200 mV-5 V

Additional Specifications

CEA-2006 Compliant: CEA-2006 is a new system of testing & measurement methods for mobile audio amplifiers. This voluntary standard advocates a uniform method for determining 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 4-ohm load, with 1% or less Total Harmonic Distortion (THD) plus noise, and at a frequency range (for full range amplifiers) of 20 Hz to 20,000 Hz. Signal-to-Noise ratio is measured in weighted absolute decibels (dBA) at a reference of 1 watt into 4 ohms. CEA-2006 allows consumers to compare car amplifiers and receivers on an equal basis.

Power: Using the CEA-2006 guidelines above, the power output of the KAC-8402 is 60 watts RMS x 4 channels.

Kenwood also lists the following specifications:

  • Rated power output at 2 ohms: 90 watts x 4 (1 kHz, 0.8% THD)
  • Rated power output at 4 ohms, bridged: 180 watts x 2 (1 kHz, 0.8% THD)
  • Input impedance: 10k ohms
  • Operating voltage: 14.4 V (11-16V allowable)
  • Current consumption: 40A

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Kenwood KAC-8402 Reviews

Average Customer Review:

9 reviews
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Good amp

Written By Upgrade, Kona, HI on Friday, January 20, 2012

This amp replaced a sony 4 ch with similar power ratings. Sound quality is a tad better than the sony but it is much more stable and powerful at 2 ohms. I am running 2 Polk DB tweeters and 2 Pioneer 6x8's off amp A @ 2ohms stereo and 2 pioneer 5x7's off amp B @ 4 ohms and they are loud and clear.

I am running 8 gauge power and ground off a capacitor in tandem with an infinity mono amp and it does fine. For the guys with problems of it shutting off I would check your ohms and your voltage. Voltage drops create extra heat.

Pros: Clarity and Power per Dollar

Cons: A tad on the large size but manageable

the amp you should get

Written By Clint, Saint joseph, Mo on Tuesday, October 19, 2010

If you know how to put a system in then you won't have a problem. I ran two 15s with it and no it never cut out. My dad and i run kenwood amps and i think they are good amps.

Great amp, great sound

Written By Seth, Huntington Station, NY on Sunday, December 17, 2006

I install car audio and security for a living, and I put this amp into my girlfriend's car today. I have 4 pioneer speakers running off the front channel (This amp will give 90 watts rms at 2 ohms). The rear channel is bridged to power a 10 inch MTX subwoofer. I have the radio set flat with the crossovers on the amp doing all the work, and it sounds great, stays cool, and gives me zero noise! Not to mention it looks nice.

Great sound when volume is moderate

Written By Angel, Los Angeles, CA on Wednesday, May 31, 2006

This is a great amp if you want to give your stock system more power with cleaner sound. I would not recommend it if like running your system LOUD!! It has horrible thermal protection and within 10 minutes of running it at over 70% power, it will automatically cut the volume and go into thermal protection mode. It is very annoying and embarrassing when you are trying to show off your system. Kenwood makes great head units/recievers, however I would never buy a Kenwood amp again. I returned the amp within 30 days and got my money back. I invested in a slghtly more expensive kicker 4 channel amp. Works great!!

Kenwood KAC-8402

Written By Kara, South Dakota on Monday, May 01, 2006

I have this powering 2 10 inch MB Quarts... The first amp I installed had some kind of manufacturing defect but Crutchfield had a new one at my house within the week. Definitely worth the money, and definitely pumps some sound.

Great Highs Amp!!!

Written By Galant_Rider87, Quitman, Georgia on Tuesday, February 07, 2006

This amp is one of the best amps that i have ever had in my car audio system. This is one amp that really dishs out the power that my speakers really need. I'm running a set of Kenwood i605s in the door with a mounted tweeter, which is screaming like a new born baby. The amp is very is easy to tune and very simple to hook up like all amps should be. All in All this amp is worth all the money that i dished out for it.
P.S. will add additional speakers such as the i705(back dash)

A Professional's Opinion

Written By Brian, Battle Creek, MI on Thursday, September 15, 2005

Crutchfield Customer Review (What's this?)

I used to install car audio for a living, and the first rule of car audio installation is to pick the right equipment for the right job. I purchased this amplifier to do what it was made to do, power full range speakers. When coupled to four Kicker 6 ½ inch speakers this amp produces excellent clean sound. Some may argue that 60 watts isn't much better than their aftermarket CD player. Consider the size and efficiency difference between your in dash amplifier and this piece of hardware, and it is easy to imagine how much cleaner and more powerful a signal you can get from a separate amp. Properly installed with a sufficiently robust power and ground wires this amp has never given me any overheat or protection problems even mounted at a 100 degree angle. Experience in the performance car audio/video world has taught me that protection and overheat issues are most often caused by installer error, not product malfunction. This product is Powerful, durable, and excellently suited for powering your full range speakers, and as always Crutchfield provides great customer service and fast delivery.

Look for another amp

Written By Frank, Millersville PA on Monday, August 29, 2005

I would not recommend this amp to anyone. It lacks the basic heat sink/radiator to properly cool the unit. I had it installed on the back of my rear seat in my 04 mustang with the KDC X889 headunit and JL components and a 10in sub and EVERYDAY that i would turn up my volume, the amp would cut out and go into thermal protect mode. I would be embarassed when i would show off my system to my friends and the sound would cut out. There is absolutely no value for dollar on this amp. I upgraded to a different brand and i do not experience any of the embarassment that i had with this amp.


Written By CodyHeiner, Houston, Texas on Wednesday, April 06, 2005

This amp is awesome!!! I have it hooked to 2 Rockford 6"x9"'s and 2 Rockford 4"'s. They are screaming thanks to this amp. I definitely would recommend this amp as a highs amp. I am definitely satisfied!!!

Get everything you’ll need to enjoy your new Kenwood KAC-8402

Bring the music from your amp to your speakers.
Patch cables take the music from your stereo to the amplifier. Most amp wiring kits don't include them.
Helps protect your car's charging system and improves power handling. Required power and ground wires not included with cap.
The right tools will make the installation easier.
Have your new amplifier put in by a qualified professional in your area.
T-Spec 12-gauge Speaker Wire

T-Spec 12-gauge Speaker Wire

Black/white jacket — priced per foot

Item #: 120SW12WB1


T-Spec 4-Channel RCA Patch Cable

T-Spec 4-Channel RCA Patch Cable

17-foot length

Item #: 120RCA174


Add to Cart
T-Spec 2-Channel RCA Patch Cables

T-Spec 2-Channel RCA Patch Cables

Available in 7 different lengths (17-foot)

Item #: 120RCA172


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EFX 17-foot RCA Patch Cable

EFX 17-foot RCA Patch Cable

Item #: 142A17C


After $2.00 Savings Add to Cart
EFX 2-Channel RCA Patch Cables

EFX 2-Channel RCA Patch Cables

Reference Series Multi-Core RCA patch cables — available in 5 different lengths (25-foot)

Item #: 142RR25


Add to Cart
EFX 2-Channel RCA Patch Cables

EFX 2-Channel RCA Patch Cables

Elite Series Braided Multi-Core RCA patch cables — available in 5 different lengths (17-foot)

Item #: 142RE17

Add to Cart
EFX 2-Channel RCA Patch Cables

EFX 2-Channel RCA Patch Cables

Core Series Twisted RCA patch cables — available in 5 different lengths (17-foot)

Item #: 142RCT17B


Add to Cart
T-Spec Capacitor

T-Spec Capacitor

1.5-farad capacitor with red LCD meter

Item #: 12015DDC


Add to Cart
S&G Tool Aid 87650

S&G Tool Aid 87650

Door Trim and Panel Removal Tool

Item #: 18187650


Skewdriver Pro SPK4042

Skewdriver Pro SPK4042

Ratcheting straight and offset screwdriver set with 40 bits (Skewdriver Pro with ratchet handle, pictured)

Item #: 180SPK4042


Add to Cart
Metra Crimp Tool and Connectors

Metra Crimp Tool and Connectors

Package contains crimp tool and over 150 pieces

Item #: 120CRIMPKT


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S&G Wire Cutter/Stripper Tool

S&G Wire Cutter/Stripper Tool

Cuts and strips 12- to 22-gauge wire

Item #: 18119100


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Install Bay IB35400

Install Bay IB35400

Premium door panel and trim tool

Item #: 12035400

Add to Cart
Install Bay 3320

Install Bay 3320

Auto-ranging digital multimeter

Item #: 1203320

Add to Cart
InstallCard: Amp or Equalizer

InstallCard: Amp or Equalizer

Prepaid professional amplifier or EQ installation

Item #: 597421003


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