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Ease of installation and killer performance are only two of the many reasons you should check out Kenwood's KAC-859 5-channel amplifier. This rugged multi-channel masterpiece has all the features found in its 4-channel brothers along with a hefty 120-watt subwoofer channel. Built-in high-pass crossovers (selectable off/80/150 Hz, 12 dB per octave) on the front and rear channels and a low-pass crossover (variable from 50-200 Hz, 18 dB per octave) on the subwoofer channel direct the different frequency ranges to their proper destinations.

Dual power supplies ensure that the 4-channel section is not affected by heavy demands on the subwoofer channel. The Input Selector sends information to all channels even if your receiver has only one set of preamp outputs. Like to keep it simple? This is the amp for you.

  • 3-, 4-, or 5-channel output
  • 40 watts RMS x 4 + 120W x 1
  • 60 watts x 4 + 150 watts x 1 at 2 ohms
  • requires 4-gauge power and ground leads — wiring and hardware not included with amplifier
  • speaker-level inputs
  • anti-thump circuit for quiet turn-on
  • speaker short, thermal overload, and DC protection
  • extra-large noise filters
  • three sets of gold-plated preamp inputs
  • signal-to-noise ratio 100 dB
  • independent power supply for subwoofer leaves 4-channel power unaffected by demands of the subwoofer
  • 50-200 Hz continuously variable low-pass crossover, 18 dB/octave (subwoofer channel)
  • selectable (80 Hz, 150 Hz) high-pass crossover, 12 dB per octave (A/B channels)
  • 15-1/8"W x 2-3/8"H x 12-5/8"D
  • 1-year warranty

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.

Kenwood KAC-859 Reviews

Hands-on research

What's in the box?

Download owner's manual

  • Dark gray 5-channel amplifier with chrome trim
  • Two 25-amp fuses in chassis
  • 4 self-tapping mounting screws
  • Rubber terminal cover
  • Manual (English/French/Spanish)
  • Warranty card

Product Research

Inputs and Outputs
More Specs


Four way protection circuitry protects the amplifier when:

  • The speaker wires are short circuited to each other or ground
  • The amplifier exceeds normal operating temperature
  • DC output to speakers is detected
  • If the amp or receiver are not properly grounded

Power MOSFET switching power supply


Variable Input Sensitivity:  The variable input sensitivity knobs allow you to adjust input levels from 0.2 to 5Volts for the front, rear, and sub preamp inputs.

Subwoofer Low-Pass Filter: The variable low-pass filter allows the crossover to operate from 50-200Hz with an 18dB/octave slope.

Front and Rear High-Pass Filters: The high-pass filters allow the crossovers to operate at 80 Hz, 150 Hz, or off with an 12dB/octave slope. There are separate high-pass filters for the front and rear outputs.

Infrasonic Filter: The infrasonic filter keeps out frequencies that are too low to be heard, but can harm the woofer, waste amplifier power and create distortion. The setting is fixed at 15Hz with an 18dB/octave slope.

Input Selector (A/AB) Switch: In the A position (front), the input for the front RCAs is output from the front and rear amps. In the AB position (front/rear), the input for the front RCAs is output from the front amp, while the input for the rear RCAs is output from the rear amp.

Input Selector (AB/SUB) Switch: In the AB position (front/rear), the inputs for the front RCAs and the rear RCAs are mixed and output from the Sub amp. In the SUB position, the input for the SUB RCAs is output from the sub amp.

Operation Switch: This switch is used to select the operation mode of the amplifier. With the switch in the STEREO position, the amp can be used as a stereo amplifier. With the switch in the MONO (Lch) position, only the signal input from the left side is amplified. Set to this position and make bridged connections to use as a high-power mono amp. 

Inputs and Outputs

  • Line In A: Front Left and Right gold plated RCA preamp inputs
  • Line In B: Rear Left and Right gold plated RCA preamp inputs
  • Line In SUB: Sub Left and Right gold plated RCA preamp inputs
  • Speaker Level Inputs (Front and Rear): Strip terminal connections are used for left and right, positive and negative (bare wire)
  • Batt: Gold plated strip terminal connections for +12V
  • GND: Gold plated strip terminal connections for ground
  • P.Con (remote): Gold plated strip terminal connections for remote turn on
  • Speaker Output (Front, rear, and sub): Positive and negative gold plated strip terminal for speaker output

More Specs

  • Max power output (peak output) at 4 Ohms: 80W x 4, 240W x 1
  • Rated power output at 2 Ohms: 60W x 4, 150W x 1 (0.8% THD at 100Hz)
  • Operating voltage for above ratings: 14.4V (11-16 allowable)
  • Current Consumption max: 48 A

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.