Kenwood built the KAC-8103D amplifier from the ground up to power your subs with authority. Its rugged cast-aluminum chassis houses an efficient mono power amp that'll punch out up to 500 watts RMS without putting a strain on your car's electrical system.

A built-in low-pass filter adjusts amplifier output so you'll get the best sound possible from your subwoofer/box combo, while the subsonic filter eliminates inaudible, ultra-low bass that can detract from your sub's performance. You can dial in up to 18 dB of bass boost if you want to fatten up the sound.

The top-mounted controls allow you to tweak the sound easily, and convenient front-side connections make setup a snap. Speaker- and preamp-level inputs, plus preamp outputs, provide flexibility in system design and hookup.

Product Highlights:

  • mono subwoofer amplifier
  • 300 watts RMS x 1 at 4 ohms (500 watts x 1 at 2 ohms)
  • CEA-2006 compliant
  • variable low-pass filter (50-200 Hz at 24 dB per octave)
  • bass boost (0-18 dB at 40 Hz )
  • subsonic filter (15/25 Hz, 18 dB/octave )
  • Class D design
  • speaker- and preamp-level inputs
  • preamp outputs
  • fuse rating: 40A x 1
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 12-7/16"W x 2-1/2"H x 11-11/16"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.

Kenwood KAC-8103D Reviews

Average Customer Review:

16 reviews
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Written By Eli, Arlington, VA on Tuesday, August 05, 2008

I have a volvo s70 with a kenwood double din HU running the stock speakers (which sound amazing for stock). I have a single sealed Alpine Type R wired up to this amp at two ohms, and it never quits thumping!!!! Sounds good on all types of music and at all volumes...I was confused because this amp had two negative and two positive speaker outputs even though it mono, im guessing thats to make it easier to wire two subs up.
I have no complaints....this amp pushes the type r well and i cant imagine it sounding better. I have used the am for nearly a year, ive had no problems, and i couldn't be more pleased. Kenwood makes great looking and sounding products at great prices. I 100% recommend this amp,kenwood, and crutchfield

Kenwood KAC-8103D

Written By Gary, Hartford, CT on Wednesday, February 20, 2008

Crutchfield Customer Review (What's this?)

Gave my sub plenty of power bazooka 10" tube

Great amp

Written By Chris, Morgantown, WV on Monday, January 28, 2008

Crutchfield Customer Review (What's this?)

I took advantage of crutchfields deal on this amp w/ 2 12" kenwood subs. I have the amp turned up less than halfway, and this setup thumps. I have these in a sealed box that I built myself.. probably about 1 cu. ft. of air per sub. Sounds AMAZING... Feels like my car (1994 Subaru Legacy wagon) is gonna explode.

I have run this amp for 2 hours straight with no issues. I have this and another amp run with Scosche wiring... 4 Gauge to a distro block, then 8 gauge to each amp.. a .5F cap inline as well... works great with no issues.


Written By ANT, Phila. PA on Thursday, January 24, 2008





Great Amp!

Written By tmx4557, Cedarhurst, New York on Monday, January 21, 2008

Crutchfield Customer Review (What's this?)

I was hesitant at first to purchase a factory refurbished amp, but I am glad I did. This amp puts out a tremendous amount of power for $100 and gives off almost no heat! The hookup was easier than most amps that I have installed because all of the terminals are on one side of the unit. It's small size made it much easier to conceal than my 4 channel amp was, it fit neatly in the spare tire compartment across from said other amp with no problems at all. The sound is great, and the ability to filter out all of the excess noise that we can't hear really does make a difference, the result is the cleanese sounding bass that I have ever had. I have these hooked up to two MTX Jackhammer 12" subs in a dual chamber sealed enclosure with 1.25' of air space in each, my scion tC booms much louder and clearer than many other cars with more expensive systems. This was a great buy!

good but has its drawbacks

Written By Stephen, cartersville, ga on Wednesday, January 16, 2008

Crutchfield Customer Review (What's this?)

amp is good, but it overheats easily.
i got this amp with 2 kenwood 12's, and if you play your music too loud it will overheat in only a minute or 2


Written By eckz59, nj on Friday, December 14, 2007

I've got this kenwood 8103D hooked up to an Alpine SWR-1042D (10" dual 4-ohm sub) in parallel, so the total impedance is 2 ohms. I have the Alpine Type-R in a Q-Logic 10" ported 1.25cft enclosure and even though the "port size" isn't what is specified by Alpine, it still sounds great. I have the high pass filter on my HU turned to 125hz and the LPF on the sub at the same, with bass boost and gain at default and it is so beautiful I could cry. The seats get punched with this combo, at quarter volume!! Do it!

Perfect for me

Written By Mr. Bill, Skagit County, WA on Wednesday, October 31, 2007

This amp is a perfect match for my single 12" DVC Infinity Reference 1250w. I have it wired at 4 ohms, because the rms on my sub is 300 watts. It hits hard! I don't need too much power because I have a Jeep Grand Cherokee. So because it is in the open (and not in a trunk) it rocks socks. This actually turned out to be much louder than I expected. But the bass hits tight and precise. Goes well with the rest of my system (Rockford Fosgate P400-4 amp connected to four Alpine 6 1/2" S-series and two polk db1000 tweets).

Exactly what I needed :D And by the way, mine doesn't overheat. My commute is 30-45 minutes.

Kenwood KAC-8103D

Written By justin, yadkinville, N.C. on Wednesday, October 10, 2007

this is the best amp ive ever owned, i have it hooked to 2 kicker cvr12's in a custom made box in my 68 vw bug and it thumps so hard that after about 2 bass hits you get a headache.

great amp

Written By B C, milton,pa on Sunday, October 07, 2007

wow. what a great amp. blows my old sony amp outa the water. have it hooked up to 3 kicker comps with the gain at about 1.5 and im shaking my 2000 olds intrigue to pieces. gona get some dynamat before my trunk explodes. and there not even facing back towards the trunk


Written By mart, Seattle WA on Wednesday, August 29, 2007

I have this amp hooked up to my 12w3 sub and it hits hard and clean. I had the same sub being pushed by a 250/1 amp and this hits much harder. GREAT BUY!!!!

excellent amp

Written By T.J., Lovington, NM on Wednesday, August 15, 2007

Crutchfield Customer Review (What's this?)

I've got this amp hooked up to 2 12" alpine type-E subs in a sealed box with 1.2 cubic ft each. The subs are rated at 250 watts rms and the amp delivers 500 watts rms @2 ohms so it's a perfect match at 250 watts per sub. I get tight, hard hitting bass with no distortion. The LPF frequency control and ISF switch bring alot to the system by allowing me to eliminate the useless ultralow freqs and tailor the useful freqs to what I want to hear. I've got everything in my work truck and I spend alot of time behind the wheel, so I work my sound system pretty hard for long periods of time and I'm not having any problems with heat or high power consumption. Most importantly this amp delivered what I was looking for most, clean, hard hitting sound and versatility. I'm not setting off car alarms in parking lots or rattling the neighbors windows but then again, I'm not trying to. But, I don't believe that type of performance is beyond it's capabilities either. In my opinion, it's an excellent amp delivering everything it boasts plus some.

kac-8103D amp

Written By jon, pennsauken, nj on Wednesday, June 27, 2007

this is a great amp if your looking low budget. i have 2 hooked up to 2 alpine type-r @ 2ohms, hits hard and can hear it coming down the street, great buy.


Written By chip, Fredericksburg, VA on Thursday, June 14, 2007

I have this amp hooked up to a single 350 RMS Sony Xplod in a ported box. This amp works excellent I have it underneath my bench seat in my 1999 Tahoe. There is not a problem with it getting too hot or anything. Hope this review helps out.

Kenwood KAC-8103D

Written By Shoe, Magazine, Arkansas on Sunday, May 13, 2007

I bought one of these to power 2 Audiobahn AW102N 10" subwoofers. This thing over heats way too much. I am probably going to get a fan for it, but if you like loud music I really do not recommend this thing. I mean, it powers the subwoofers nicely, but just overheats like my old Sony amp.

amazing output

Written By Soaupplysa, Dallas,Tx on Friday, March 16, 2007

incredible output. Easy to install. Delivers amazing power to my 12 inch Kenwood sub.

Hands-on research

What's in the box?

Download owner's manual

  • Mono amplifier with one 40-amp fuses inserted into the chassis
  • Speaker-level input harness
  • 4 Self-tapping screws
  • 2 Rubber terminal covers
  • Instruction Manual (English/French/Spanish)
  • Warranty Card

Product Research

Inputs and Outputs


CEA-2006 Compliant: CEA-2006 is a new system of testing and 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 of 20 Hz to 200 Hz when applicable. 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. The Kenwood KAC-8103D under CEA-2006 regulations is rated at 300 Watts RMS x 1 channel with a 85dBA signal to noise ratio.

Mono-Power Amp Design: The Kenwood KAC-8103D is designed with specific features to power your subwoofers with a frequency range between 5-200 Hz. This amplifier is not designed to power a full-range speaker.

2-Ohm Stable: The Kenwood mono-amplifier is capable of handling load impedances down to 2-ohms. The amplifier is rated at 500 Watts RMS x 1 channel in 2 ohms at 100Hz with 0.8% THD.

Class D Amplifier Design: The KAC-8103D is a Class D mono-block amplifier, which uses digital switching to amplify audio signals. This design results in high efficiency and less heat.

MOS-FET Switching Power Supply: The amplifier utilizes a MOS-FET switching power supply providing thermal stability and efficient switching speeds guaranteeing performance and dependability.

Parallel Connection: The amplifier is equipped with two pairs of gold-plated speaker terminals for an easy parallel subwoofer connection.

Low-Pass Filter: The KAC-8103D has a built-in 24dB/octave low-pass filter that is continuously variable from 50Hz to 200Hz.

Bass Boost: The bass boost is adjustable from 0-18dB at 40Hz.

Infrasonic Filter: This amp features an 18dB/octave Infrasonic Filter. Ultra-low frequencies that cannot be reproduced by a subwoofer do not become sound but become unnecessary oscillations, which affect sound by causing distortion. These frequencies also waste amplifier power and can cause damage to speakers. Setting the Infrasonic filter switch to 15Hz or 25Hz cuts the frequencies below the respective frequency to improve the reproduction performance of the speakers by eliminating harmful distortion.

Line Level Inputs: The RCA type line-level inputs have a gain (Input Sensitivity) control. The Input Sensitivity control will accept an input signal of 200mV to 5.0 Volts.

Speaker Level Input: The KAC-8103D comes with a speaker level input harness. This feature makes it easier to add an amplifier to a factory radio or to a receiver with no preamp outputs.

Line Level Output: The amplifier has a set of line level outputs for feeding a full-range stereo signal to another amplifier. It is the same signal that is input through the line inputs. The amplifier's crossovers have no effect on the line level output signal.

Power Indicator: When the power is turned on to the amplifier, the Power indicator will light up. This indicator will turn off with the amplifier and will turn off if the amplifier goes into protect mode.

Protection circuitry: The amplifier features protection circuits that will turn the amp off in case of the following events to protect the amplifier and your speakers:

  • 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


Front of the Amplifier: All of the amplifier's controls are found on the front of the amplifier.

  • Bass Boost Level: 0-18 dB
  • Low Pass Frequency: 50-200 Hz
  • Input Sensitivity: 200mV-5V
  • ISF Switch: 25Hz, 15Hz or off

Inputs and Outputs

Front of the Amplifier: All of the amplifier's connections are found on the front of the amp.

  • Fuses: One 40A fuse
  • Power: Gold-plate screw terminal (0.5625" wide)
  • Ground: Gold-plate screw terminal (0.5625" wide)
  • Remote Turn-on: Gold-plated screw terminal (0.3125" wide)
  • Speaker Outputs: Two pair of gold-plated screw terminals (0.3125" wide)
  • Line In: One pair of gold-plated RCA inputs
  • Line Out: One pair gold-plated RCA outputs
  • Speaker-level Input: Multi-pin input for use with included speaker level input harness

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.