Kenwood KAC-M1804

4-channel amplifier — 45 watts RMS x 4

Item #: 113KAM1804

In Stock

2 Reviews | 2 questions - 3 answers

Your price: $149.99 Earn up to 150 Rewards points

Add to Cart Free Shipping Lifetime Tech Support

+ Add to wishlist + Email me alerts for this product

View all associated offers

Power your speakers on land or sea

Kenwood's KAC-M1804 4-channel amplifier will pump up your car's audio system with 45 watts RMS per channel — that's more than twice the power of most car stereos. The super-compact KAC-M1804 will add new clarity and impact to the basic sound system of almost any kind of vehicle on land or water, and it'll fit in a lot of places when space is tight. The amp uses plastic covers to protect its connections and features a conformal coated circuit board that keeps out moisture and salt, so the party won't stop just because of a little wetness.

Hooks up to almost any system

The KAC-M1804 comes with an RCA cable for connecting to an aftermarket receiver, but it can handle speaker-level signals as well, so you can still get input from a radio without RCA outputs. The amp senses incoming high-level signals and turns itself on, eliminating the need to install a separate remote turn-on wire.

If your receiver's power circuit is protected by a 15-amp or larger fuse (check your fuse box or owner's manual), you can tap into it to power your KAC-M1804. Otherwise, you'll have to run a power wire to the battery and install a 15-amp inline fuse as close to the battery as possible.

Product Highlights:

  • compact 4-channel amplifier for car, motorcycle, and boat
  • 45 watts RMS (100 watts peak) x 4 at 4 ohms
  • non-bridgeable, 4-ohm stable per channel
  • CEA-2006 compliant
  • MOSFET power supply and Class D amp technology
  • conformal-coated circuit board — suitable for marine applications
  • preamp and speaker-level inputs
  • signal-sensing turn-on on speaker-level inputs eliminate need for a separate remote lead
  • RCA cables and short power/speaker harness included
  • 10-gauge power and ground leads recommended
  • fuse rating: 15A x 1
  • dimensions: 6-1/2"W x 1-3/8"H x 3-9/16"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

  • 4-Channel amplifier with a 15A ATM fuse installed
  • Two 38" RCA stereo patch cables
  • 5' Power and speaker output harness
  • 4 Self-tapping screws (Length=5/8")
  • Two 13.5" plastic wire ties
  • Two 4" plastic wire ties
  • Instruction Manual/Warranty sheet

Product Research

Features
Connections

Features

Compact Amplifier: The Kenwood KAC-M1804 compact Class D 4-channel amplifier is designed to boost the output and clarity of your car stereo. The amp features a conformal coating on the circuit board to protect it from moisture. This allows you to use the amp for marine applications, or on All-Terrain Vehicles (ATVs). The KAC-M1804 delivers 45 watts RMS x 4 channels at 4 ohms. It cannot be bridged or operated at impedances less than 4 ohms.

Protection Circuitry: The amplifier features protection circuitry for thermal overload, DC offset, and short circuits. The amp stops operating when it goes into protection mode. (There are no LED indicators.)

Signal-sensing Turn-on: When the amplifier is connected to a factory head unit, or an aftermarket unit without preamp outputs, you can cut off the amp's RCA input connectors and splice the head unit's speaker wires to the input wires. In this case, the amplifier's Signal-sensing Turn-on feature will turn on the amp when a signal is detected on the input. This eliminates the need to connect a turn-on lead to the amp's Power Control (blue) wire.

No Controls or Crossovers: The KAC-M1804 does not have built-in crossovers or controls. If you are connecting the amp to small speakers, it is recommended that you use the crossovers built into the connected head unit, or use bass blockers on the speaker outputs.

Connections

Amp Wiring: The Kenwood KAC-M1804 is equipped with a 22-pin DC connector on the amplifier. The included 5' DC harness, which plugs into the connector, has wires for +12V battery power, ground, power control (turn-on lead), and four speakers.

Power/Ground: The +12V Power and Ground wires are 16 AWG wires. The power wire can be connected to the car's fuse box or directly to the battery. The amp is protected by a 15A ATM mini blade fuse. If wiring directly to the battery, you can use a 10 AWG wire with an in-line 15A fuse installed no more than 18" from the battery terminal. The ground wire should be attached to a metal area close to the amplifier.

Power Control: The blue Power Control wire should be connected to the head unit's remote turn-on lead when an aftermarket unit is used. This wire does not need to be connected if you're using speaker level inputs. The Signal-sensing Turn-on feature will turn on the amplifier when an input signal is detected.

Line-Level Inputs: The amplifier is equipped with two pairs of RCA inputs on 7-1/2" pigtails for connecting stereo RCA patch cables from the head unit to the amp. Two 38" stereo RCA patch cables are included. If using a factory head unit, or a unit without preamp outputs, you can cut off the RCA jacks and splice the four speaker wires to the two inputs, maintaining the same polarity.

Speaker Outputs: The included DC harness has eight wires for connecting four speakers to the amp: Front left (white + white/black), Front right (gray + gray/black), Rear left (green + green/black), and Rear right (purple + purple/black). The amp is not capable of bridging or connecting to speakers with impedances less than 4 ohms.

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 open the box, verify contents, 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-M1804 Reviews

Average Customer Review:

2 reviews
Review this product
Great Gear Giveaway

Submit a review and then enter to win a $500 rewards card

(0)
(0)
(0)
(0)
(0)

Review this product:

Thanks for taking the time to share your experiences about this product. Please be sure to focus your comments on the product itself. Read our Review Guidelines for more information.

Your email won't be visible. Please use the email address that is associated with your order.
(e.g., JohnD) Your review will be signed using the display name and location
(e.g., Charlottesville, VA)

Click on a star to rate the overall product on a scale of 1-5
1500 characters left
  Attach a YouTube Review
Crutchfield Video Review Guidelines
  • Only submit videos that you made or are authorized to use.
  • Do not submit videos that contain music, video or visuals that are copyrighted and belong to someone else.
  • Please see our Review Guidelines for more information.
500 characters left
500 characters left

Great Amp

Written By Roxy85, Virgilina, VA on Thursday, June 19, 2014

Crutchfield Customer Review (What's this?)

Easy to install-very compact. Produces great sound

Pros: Install was very easy, very compact and water proof.

Cons: None

good amp for the $

Written By Eric, whitesburg ga on Saturday, June 14, 2014

Crutchfield Customer Review (What's this?)

I bought this amp to boost the sound on my pontoon boat and am very pleased. Sound quality is fantastic. I can run 20 mph and hear my radio now over the water and wind noise. Great amp for the money.

Pros: Good value

Cons: none

Get everything you’ll need to enjoy your new Kenwood KAC-M1804

You'll need an amp wiring kit to install your new amplifier, as wiring is not included.
Patch cables take the music from your stereo to the amplifier. Most amp wiring kits don't include them.
The right tools will make the installation easier.
Have your new amplifier put in by a qualified professional in your area.
Bring the music from your amp to your speakers.
EFX PA10BX Wiring Kit

EFX PA10BX Wiring Kit

10-gauge amplifier wiring kit — includes 2-channel patch cable

Item #: 142PA10BX

(7)

$29.99
Add to Cart
Rockford Fosgate RFK10i

Rockford Fosgate RFK10i

10-gauge amplifier power and signal wiring kit

Item #: 575RFK101

(41)

$49.99
Add to Cart
T-Spec 2-Channel RCA Patch Cables

T-Spec 2-Channel RCA Patch Cables

Available in 7 different lengths (10-foot)

Item #: 120RCA102

(27)

$14.99
Add to Cart
T-Spec 4-Channel RCA Patch Cable

T-Spec 4-Channel RCA Patch Cable

17-foot length

Item #: 120RCA174

(8)

$29.99
Add to Cart
EFX 17-foot RCA Patch Cable

EFX 17-foot RCA Patch Cable

Item #: 142A17C

(55)

$7.99
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 (12-foot)

Item #: 142RR12

$19.95
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 (12-foot)

Item #: 142RCT12B

$9.95
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 (25-foot)

Item #: 142RE25

$99.95
Add to Cart
Metra Crimp Tool and Connectors

Metra Crimp Tool and Connectors

Package contains crimp tool and over 150 pieces

Item #: 120CRIMPKT

(15)

$19.99
Add to Cart
Metra Crimp Tool Set

Metra Crimp Tool Set

Package contains light-duty crimp tool and 20 crimp caps

Item #: 120RCVRKIT

(29)

S&G Wire Cutter/Stripper Tool

S&G Wire Cutter/Stripper Tool

Cuts and strips 12- to 22-gauge wire

Item #: 18119100

(17)

$19.99
Add to Cart
S&G Tool Aid 87650

S&G Tool Aid 87650

Door Trim and Panel Removal Tool

Item #: 18187650

(71)

Pro.Fit Hook Tool Set

Pro.Fit Hook Tool Set

Installation tools — pair

Item #: 042DM3022

(9)

Pro.Fit Trim Panel Tool

Pro.Fit Trim Panel Tool

Remove your vehicle's trim panels without damage

Item #: 042DM4022

(88)

Pro.Fit Wire Worm

Pro.Fit Wire Worm

Installation tool helps route wiring through tight spaces

Item #: 042DM4533

(34)

$12.99
Add to Cart
Bojo Trim Panel Tools

Bojo Trim Panel Tools

Set of 6 pry tools — helps remove interior and exterior trim and door panels

Item #: 126CR6LNGL

(2)

$29.99
Add to Cart
Bojo Trim Panel Tools

Bojo Trim Panel Tools

Set of 6 pry tools — helps remove interior and exterior trim and door panels

Item #: 126CR6NGL

(54)

$24.99
Add to Cart
Skewdriver Pro SPK4042

Skewdriver Pro SPK4042

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

Item #: 180SPK4042

(8)

$49.99
Add to Cart
Install Bay IB35400

Install Bay IB35400

Premium door panel and trim tool

Item #: 12035400

$15.99
Add to Cart
Install Bay 3320

Install Bay 3320

Auto-ranging digital multimeter

Item #: 1203320

$39.99
Add to Cart
Posi-Products™ Car Stereo Connectors

Posi-Products™ Car Stereo Connectors

16 connectors for installing a new car stereo

Item #: 669PP500

(711)

Metra Crimp Caps

Metra Crimp Caps

Package contains 100 crimp caps — for 14- to 16-gauge wire

Item #: 120CCL1614

(62)

DEI Heat Shrink Tubing

DEI Heat Shrink Tubing

Black 4-foot length (Assortment)

Item #: 696010839

(8)

$24.99
Add to Cart
InstallCard: Amp or Equalizer

InstallCard: Amp or Equalizer

Prepaid professional amplifier or EQ installation

Item #: 597421003

(18)

$79.99
Add to Cart
Metra SW18 18-gauge Speaker Wire

Metra SW18 18-gauge Speaker Wire

Clear jacket — priced per foot

Item #: 120SW181K

(2)

T-Spec 16-gauge Speaker Wire

T-Spec 16-gauge Speaker Wire

Black/white jacket — priced per foot

Item #: 120SW16WB1

(13)

Stinger PRO Series Speaker Wire

Stinger PRO Series Speaker Wire

Priced per foot (14 Gauge)

Item #: 541SPW514B

(52)

$0.65
Add to Cart
T-Spec Power/Ground Cable

T-Spec Power/Ground Cable

Available by the foot in pearl or gray — marine-certified (10-ga. Pearl)

Item #: 120PW101

(7)

Questions & Answers Ask the community. Share your knowledge.

2 questions already asked

I have a 2013 HD Street Glide. Will this amp plug easily into the factory radio or will I need to have it professionally installed? [ Brad  Jul 23, 2014 ]
The input level is set automatically. There are no controls. That said, I am very happy with the unit. It takes up very little space and the sound quality is excellent. [ Thomas  Jul 19, 2014 ]
I forwarded your question to an Advisor and they responded with the following: It's perfectly fine to slightly overpower your front speakers, so the 45 watts will work in this application. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Jul 11, 2014 ]  Staff