You put some good bass in your car, but now your speakers just aren't hanging with your subs. Kicker designed their KS Series speakers to deliver the performance you need to bring that "live music" experience to your ride.

The KS40 4" 2-way speakers use heavy-duty polypropylene cones supported by Santoprene rubber surrounds. Each speaker sports a 1/2" balanced dome tweeter that broadcasts plenty of high-frequency sparkle, so you'll hear all the sonic details that make your tunes exciting.

Product Highlights:

  • 2-way 4" speakers (pair)
  • polypropylene woofer cone with Santoprene™ surround
  • 1/2" polyethylene naphthalate (PEN) film balanced dome tweeter
  • power range: 6-30 watts RMS (60 watts peak power)
  • frequency response: 60-20,000 Hz
  • sensitivity: 88 dB
  • top-mount depth: 1-7/8"
  • warranty: 1 year
  • Our 60-day money-back guarantee

Hands-on research

What's in the box?

Download owner's manual

  • Two 4" Coaxial speakers
  • 2 Grilles
  • 2 Grille rings
  • Two 12" lengths of speaker wire (tinned wire on one end and 0.205" + 0.110" female quick slides on the other)
  • 4 Red plastic butt connectors
  • Eight 1" Self-tapping screws
  • 8 Speed clips
  • Owner's manual (English/ Spanish/ German/ French)

Features and Specs

Design 2-way
Tweeter Design 1/2" Balanced Dome
Tweeter Composition Polyethylene Naphthalate
Woofer Composition Polypropylene
Woofer Surround Santoprene
Parts Warranty 1 Year
Labor Warranty 1 Year
Sensitivity 88 dB at 1 watt
Frequency Response 60 - 20k Hz
RMS Power Range (Watts) 6-30
Peak Power Handling (Watts) 60
Impedance (Ohms) 4
Top-mount Depth (Inches) 1 7/8
Bottom-mount Depth (Inches) 2 1/8
Cutout Diameter or Length (inches) 3 3/4

Product Research


Polypropylene Woofer Cones: The Kicker KS-series speakers feature durable polypropylene woofer cones for power and control. Polypropylene is also resistant to the moisture and temperature extremes found in automotive applications.

Santoprene Surrounds: The woofer surrounds are made of Santoprene rubber to allow extended cone excursion for additional bass output and higher SPL. Santoprene is durable and resists moisture for a long life.

Balanced Dome Tweeters: The 1/2" PEN (Polyethylene Naphthalate) balanced dome tweeters provide a smooth high frequency response with a wide dispersion pattern. The tweeters have strong neodymium magnets for higher power handling.

Grilles: The KS40s come with a pair of graphite-colored, plastic, spoke-style speaker grilles.

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.

Kicker KS40 Reviews

Average Customer Review:

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Written By Darryl, Mt pleasant on Saturday, January 11, 2014

Crutchfield Customer Review (What's this?)

Cannot beat for the money. Great upgrade speaker for my daughters first car/4 Runner.

Pros: Sound quality and perfect fit

Cons: None

Best Speaker For The Money

Written By Gmastro, Orient,Oh on Tuesday, October 01, 2013

Crutchfield Customer Review (What's this?)

After installing, which was a breeze, the sound is unbelievable! When you factor in the cost it is the best value for the dollar I have found to date.

Pros: Ease of install and cost

Cons: none found

Can expect nothing else

Written By Ralereco, 94025 on Tuesday, July 09, 2013

Crutchfield Customer Review (What's this?)

Excellent the delivery and accuaracy of descriptionn of the product was the expect thanks


Written By bob101, Eau Claire, WI on Monday, April 29, 2013

Crutchfield Customer Review (What's this?)

Speakers sound great! No complaints

Pros: sound

Cons: none

Great Speaker

Written By Josh M, Michigan on Tuesday, January 08, 2013

Crutchfield Customer Review (What's this?)

Great speaker to put in any vehicle to help the music sound crisp. The speakers are clear and do not crackle when turned up. Some people say they crack when they turn them up but obviously you shouldn't crank up brand new speakers.

Pros: Good buy. Very Satisfied.

Cons: No cons so far.

Not quite up to original equipment standard

Written By CraigM, Perryville, MD on Monday, December 17, 2012

I was hoping these would be as good as the Toyota Avalon original equipment 4" component speaker and tweeter but I am very disappointed. The original speakers sounded so much better (until they fell apart from old age!). Now I have very thin sounding speakers that I am already looking to replace. These are a waste of money. I did notice the original speakers had magnets that were twice the size and the cones had twice the depth of the kicker. My advice --- look to pay more for a better product.

Pros: Easy to mount.

Cons: Terrible tinny sound. Base response is poor.

Kicker KS40

Written By BMW, Lugoff, SC on Monday, December 17, 2012

Crutchfield Customer Review (What's this?)

For the size and type, not a bad sound. I kept the stock reflex box of my '95 325is intact, these are in the package tray of the rear window. These stock boxes are ported, an opening of about 1/2 x 2, I shoved some cotton-based batting material inside of them except around the port wave zone and the low-end response is impressive. I am only pushing about 30 watts as I am using the stock Harmon-Kardon amp. Just don't push this speaker, it's not designed for it.

Pros: For the cost, it's a good upgrade to the factory ones, although, after 17 years, the factory ones were worn out.

Cons: The only caveat, (if you can call it that) is that to put these in the stock boxes, I had to snip off 2 of the 4 mounting tabs. But, with them being serrated, they are designed that way. They were also a tad bit smaller in circumference then factory, so I sealed the gap with silicon. As it turned out, doing that forces the free air out the port - making for lower-end!

good speakers

Written By me sir, Washington, UT on Thursday, October 18, 2012

Crutchfield Customer Review (What's this?)

For such a small speaker it does a good job providing a wide variety of sounds however it struggles slightly (as expected) when it comes to bass but in all I am satisfied with my purchase

Pros: good for maintaining highs in a primarily bass system

Cons: lots of treble moderate bass

Kicker KS40 installed in 1994 Geo Metro

Written By xtf16, Tampa, FL on Tuesday, October 09, 2012

Crutchfield Customer Review (What's this?)

I ordered these speakers 5 days ago (counting the weekend) and they arrived. I could have purchased these speakers elsewhere for a little less, but I'm glad I ordered them from Crutchfield. Not only was the product instruction sheet included, but also a sheet that showed exactly how to install them in my 1994 Geo Metro. Also included for free was the wiring harness I would need to fit each speaker into my car. I just put this little old car back on the road with a new engine because it gets such great gas mileage...I thought I was going to have trouble finding speakers for it because the car is 18 years old.. but Crutchfield had the right speakers and the installation was a breeze... I am a female and anyone could get these speakers installed in a jiffy with the great info from Crutchfield. I received an email to acknowledge my order, another one when it shipped, and another to tell me that it was delivered! I also have earned points with my very first purchase by registering for free! Great service Crutchfield! A great experience doing business with you!

Kicker KS40

Written By jlrfd13, pocatello id on Tuesday, April 03, 2012

Crutchfield Customer Review (What's this?)

sound great

Pros: sound great

Cons: none so far

Get everything you’ll need to enjoy your new Kicker KS40

Reduce ambient road noise and your vehicle's "rattles," for better sound inside your car.
You may need speaker wire to connect your speakers to your amp or receiver.
Keep your speakers clean and dry. They compress to fit behind your speakers.
These speaker connectors are handy if you're running new speaker wire or if your speakers have oversized terminals.
The right tools will help keep your installation simple and clean.
If your stereo doesn't cut the deep bass from your full-range speakers, a set of bass blockers can help prevent distortion and give you cleaner bass too.
Dynamat 10415 Xtreme Speaker Kit

Dynamat 10415 Xtreme Speaker Kit

Two 10-in. x 10-in. Sheets

Item #: 15410415


Add to Cart
Dynamat 10435 Xtreme Door Kit

Dynamat 10435 Xtreme Door Kit

With four 12" x 36" sheets — covers two doors

Item #: 15410435


Add to Cart
Dynamat SuperLite Tri-Pak

Dynamat SuperLite Tri-Pak

Triple package — 3 sheets, 12 square feet (Model #10612)

Item #: 15410612


Add to Cart
T-Spec 16-gauge Speaker Wire

T-Spec 16-gauge Speaker Wire

Black/white jacket — priced per foot

Item #: 120SW16WB1


T-Spec 12-gauge Speaker Wire

T-Spec 12-gauge Speaker Wire

Black/white jacket — priced per foot

Item #: 120SW12WB1


Stinger PRO Series Speaker Wire

Stinger PRO Series Speaker Wire

Priced per foot (16 Gauge)

Item #: 541SPW516B



XTC 4" Speaker Baffles

Protect your speakers (3-7/8" depth)

Item #: 237XT40


Add to Cart
Boom Mat 4

Boom Mat 4" Speaker Baffles

Protect your speakers
Regular and slim-line sizes (Regular: 3" depth)

Item #: 696B050310


Add to Cart
Metra Female Quick Slides

Metra Female Quick Slides

An assortment of female quick slide connectors for connecting to speaker terminals

Item #: 120FQS10PK


Metra Crimp Tool and Connectors

Metra Crimp Tool and Connectors

Package contains crimp tool and over 150 pieces

Item #: 120CRIMPKT


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


Add to Cart
S&G Wire Cutter/Stripper Tool

S&G Wire Cutter/Stripper Tool

Cuts and strips 12- to 22-gauge wire

Item #: 18119100


Add to Cart
S&G Tool Aid 87615

S&G Tool Aid 87615

Window and Door Clip Removal Tool

Item #: 18187615


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
Spec Tools SQR-200a Squeeze Wrench

Spec Tools SQR-200a Squeeze Wrench

Narrow space ratchet kit with 18 sockets

Item #: 180SQR200A


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


Add to Cart
Posi-Products™ Car Speaker Connectors

Posi-Products™ Car Speaker Connectors

8 connectors for installing car speakers

Item #: 669PP502


Add to Cart
DEI Heat Shrink Tubing

DEI Heat Shrink Tubing

Black 4-foot length (Assortment)

Item #: 696010839


Add to Cart
Bass Blockers

Bass Blockers

Pairs (300 Hz cut-off)

Item #: 127BB300A2


Add to Cart

Questions & Answers Ask the community. Share your knowledge.

1 question already asked

You will want to contact an Advisor by phone or online chat to discuss compatibility with your vehicle. They will be able to help you make the best choice for your system and your budget. [ Jeff  Jan 06, 2014 ]  Staff