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Kenwood KAC-8406

4-channel car amplifier — 70 watts RMS x 4 (Factory Refurbished)

Item # 613KAC8406

Kenwood makes tough, rugged amplifiers that bring you superior sound quality along with reliable performance.

Read more from Crutchfield writer, Buck P.

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Factory Refurbished

$129.99 -$10.00 Price break

$119.99

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About the Kenwood KAC-8406

Reliable performer

Kenwood makes tough, rugged amplifiers that bring you superior sound quality along with reliable performance. Add the Kenwood Performance Series KAC-8406 amplifier to your system, and you'll hear all the tonal color, impact, and detail you've been missing, from the punch of the rhythm section to the shiver induced by your favorite singer's voice.

Reliable performer

Kenwood makes tough, rugged amplifiers that bring you superior sound quality along with reliable performance. Add the Kenwood Performance Series KAC-8406 amplifier to your system, and you'll hear all the tonal color, impact, and detail you've been missing, from the punch of the rhythm section to the shiver induced by your favorite singer's voice.

Versatile power

The KAC-8406 4-channel amp delivers 70 watts RMS per channel to your full-range speakers. This amp will bring new life to your factory speakers, but you'll really notice the difference when you pair it up with new aftermarket speakers or components. Switch the amp over to 2-channel mode, and you can get great performance from a set of high-power components or a couple of subs with up to 200 watts RMS per channel.

This versatile amp features separate frequency filters for the front and rear channels, along with speaker-level inputs and signal sensing turn-on, so you can put this amp to work in just about any kind of system. Aluminum cover plates protect the amp's connections and controls, giving your installation a neat, professional look.

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Product highlights:

  • 4-channel car amplifier
  • 70 watts RMS x 4 at 4 ohms (100 watts x 4 at 2 ohms)
  • 200 watts RMS x 2 bridged at 4 ohms (4-ohm stable in bridged mode)
  • CEA-2006 compliant
  • variable high- and low-pass filters (50-200 Hz, 12 dB per octave)
  • switchable bass boost (0, 18 dB at 40 Hz)
  • Class AB design and MOSFET power supply
  • speaker-level inputs with signal sensing turn-on
  • preamp inputs
  • fuse rating: 25A x 2
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 13-3/16"W x 2-1/4"H x 7-5/8"D
  • warranty: 90 days
  • Our 60-day money-back guarantee
  • MFR # KAC-8406
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What's in the box:

  • Refurbished 4-Channel amplifier
  • Two 25 amp ATO fuses (installed)
  • 2 Terminal covers (installed)
  • 7" Speaker-level input harness
  • 2.5mm Allen wrench
  • Four 5/8" Self-tapping screws
  • Instruction manual (English/ French/ Spanish)
  • Warranty information

Customer reviews

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Kenwood KAC-8406 Reviews

Average Customer Review(s):

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Crutchfield response

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Features
Controls
Connections

Features

CEA-2006 Compliant: CEA-2006 is a system of testing and measurement 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 standards allow consumers to compare car amplifiers and receivers under the same conditions (apples to apples). Using CEA-2006 criteria, the Kenwood KAC-8406 is rated at 70 watts RMS x 4 channels with an 80 dBA signal to noise ratio. The signal to noise ratio at the rated power output (not CEA-2006 conditions) is 100 dB.

2-Ohm Stable: The amplifier can support a 2-ohm load in stereo; the 2-ohm power output is 100 watts RMS x 4 channels.

Bridgeable: Each half of the four-channel amplifier can be bridged into a 4-ohm mono load; the bridged output is 200 watts RMS x 2 channels. If you prefer, just half the amp can be bridged for three-channel operation (70 watts RMS x 2 channels + 200 watts RMS x 1 channel).

Cast Aluminum Heat Sink: The KAC-8406 utilizes a cast aluminum heat sink design to ensure the amplifier stays cool.

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

  • speaker wire short-circuits
  • speaker output contacts ground
  • unit malfunctions and DC is sent to speaker output
  • the amp overheats

Power Indicator: When the amplifier is turned on the Power indicator (on top of the amp) lights up. This indicator turns off with the amplifier, and will turn off if the amplifier goes into protect mode.

Auto Turn-on: When using a speaker level input, the amp will turn on automatically when it senses the input signal.

Controls

Gain: To accommodate the varying range of signal levels from today's factory and aftermarket radios, the KAC-8406 features an adjustable gain control; 0.2-5.0 volts line level (RCA) and 4.0-12.0 volts speaker level.

Crossover: The four-channel amp is separated into two halves, labeled A and B. The A channel and B channel crossovers have independent controls:

  • Mode: high pass, low pass, or off (full range)
  • Frequency: rotary dial; continuously variable from 50 Hz to 200 Hz

Bass Boost: The bass boost circuit provides an 18 dB signal boost centered at 40 Hz; the bass boost is manually turned on or off.

Connections

Power Connections: The power and ground connections are 0.55" wide screw terminals. The remote turn-on screw terminal is 0.35" wide. A Phillips-head or flat blade screw driver (not supplied) is required to tighten/loosen the terminals. Spade connectors are recommended. The manual lists a minimum of 10 gauge wire for power and ground, but given the 50 amp fuse value and the current consumption specification of 35 amps, we recommend an 8 gauge wiring kit.

Speaker Outputs: The four pair of speaker outputs are 0.35" wide screw terminals. A Phillips-head or flat blade screw driver (not supplied) is required to tighten/loosen the terminals. Spade connectors are also recommended for the speaker wires.

Line Level Input: The line input is two pair of stereo RCA jacks (A-channels and B-channels).

Speaker Level Input: A wiring harness is included for the speaker level input.

Fuse: The amplifier uses two 25-amp ATO blade-type fuses.

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Customer Q&A

Q
Crutchfield asked: Why did you buy this?
A
A versatile fan cooled amp the was the right size and power!! [ Aaron  Jun 22, 2017 ]
A
Quality [ John  May 13, 2016 ]
A
Perfect amp for the system I am building. Great performance, quality brand, and fan cooled so it can be used in places with poor air flow, like behind/under the seats of a pick-up. [ James  Mar 08, 2016 ]
A
The bass boost is important to me, as is the size that will fit under the front passenger seat. The fuse size is better than a competitive amp at 50 amps, instead of 80. Fan cooling is a safety feature that's a plus. Total harmonic distortion is competitive. The overriding decision-making trigger for me is the controls the amp allows. [ Robert R  Dec 06, 2015 ]
A
great amp for my regular speakers [ nathaniel  Aug 13, 2018 ]
A
Needed it [ Robert  May 10, 2018 ]
A
Replacing old amp over! [ HARRISON M  Oct 18, 2017 ]
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5 questions already asked

Q
Would this be able to push a 200W RMS sub (bridging two of the channels) along with two aftermarket 70W coaxial speakers on the other two channels, using a factory head unit and a LOC like the LC2i?
[ Pat  Feb 21, 2016 ]
1 answer
A
Yes, each half of the four-channel amplifier can be bridged into a 4-ohm mono load; the bridged output is 200 watts RMS x 2 channels. If you prefer, just half the amp can be bridged for three-channel operation (70 watts RMS x 2 channels + 200 watts RMS x 1 channel). I hope that helps. My Bio: http://www.crutchfield.com/Support/Bio.aspx?bio=159
[ Larry  Feb 25, 2016 ]  Staff
Q
Will this push an 8inch Kicker 250rms AND a 6 speaker soundbar at 200 watts?
[ oneupmshrm  Feb 08, 2016 ]
1 answer
A
Each bridged output will put out 200w RMS. The 8" kicker should be fine, I have a 300w RMS 10" kenwood sub bridged across both channels of the b output and mine sounds great. I have managed to overheat the sub once on a hot day at high volume for a sustained period of time driving my sub and a pair of 100w kicker component speakers but only once. I'm very happy with the amp in general. This soundbar you mention is a little vauge, 6 speakers in a circut can drop your ohm's down though so I'm a little worried about that. Here's something I would give a read: http://cie-wc.edu/Series_Parallel_9_14.pdf The specs on the amp list the output at various ohm's so you should have a decent idea if it'll be adequate once you know the requierments for the sound bar.
[ GUSTAV  Feb 09, 2016 ]
Q
I recently installed this amp along with the kenwood ddx491hd head unit. I'm finding that once you turn the volume to mid volume, it pops and the amp shuts off. It's happening when you first turn on the car, so it's not overheating. It's hooked up to 2 6x9's and 2 6 1/2s. Any suggestions?
[ John K  Dec 29, 2014 ]
4 answers
A
From what I remember, a couple of things that cause amp to shut off. Make sure amp case is not grounded. Shorts in speaker cable. I would think maybe the higher the volume, the more power being pushed out, and the cable could be "ok" until that point is reached. Just a dumb thought.
[ Kevin  Dec 11, 2015 ]
A
Sorry how is the system hooked up power wise?
[ KENNETH  Jan 09, 2015 ]
A
Your in what they call cut off. How is it hooked up?
[ KENNETH  Jan 09, 2015 ]
A
I had something similar happen to me. I have a Sony deck and discovered that I had the wrong gain setting. After I moved the gain to a higher number setting the problem went away. The system really cranks now!!!
[ Aaron  Dec 29, 2014 ]
Q
Is this Amp too much for my 4 Kenwood 6x8 360 Watt 81 RMS speakers? Store guy says good match buddy says too much.... Ive got a 500 Watt Rockford Bass but separate Amp
[ Wolfman  Jan 21, 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  Jan 21, 2017 ]  Staff
Q
Can this amplifier be added to a factory head unit?
[ Chris  Dec 09, 2015 ]
3 answers
A
Yes it can. That is how mine is hooked up now. I forget the name of this type of hookup, but the amp is "spliced" in to be between the speakers and the head unit. So unless you install this amp under your dash, you will need to run 2 sets of wires. One set goes from radio to amp. The other set is from amp to speakers. The price is good. This amp was recommended to me from a Crutchfield rep and I am very happy with it.
[ Kevin  Dec 11, 2015 ]
A
I think it will work with a factory head unit, you will just have to figure out the wiring color codes which should not be to hard.
[ Thomas Moorhead  Dec 11, 2015 ]
A
Yes it can, that is the reason I purchased it. It has a feaature that senses the sound from the factory radio and then it turns on the amplifier, makin it easy to add to a factory head unit.
[ nelson  Dec 10, 2015 ]
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