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Kicker 40CWR84

CompR Series 8" subwoofer with dual 4-ohm voice coils

Outlet: Scratch & Dent

Item #: 20640CWR84

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7 Reviews


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Brace yourself 

Kicker designed their CompR line of subs for people who love to hear strong bass when their music's playing. Built from the ground up with performance in mind, these subs handle plenty of power to give you the baddest bass available from the legendary Comp line.  

Kicker 40CWR84

Change this subwoofer's impedance with a flick of the built-in switch.

Overbuilt? More like built just right

Kicker's 40CWR84 8” subwoofer comes equipped with a tough, polypropylene cone that stays rigid during intense play sessions so you hear accurate bass. A custom-designed back and top plate give the woofer plenty of room to travel, while the durable rubber surround helps to control cone movement during a heavy workout. This sub uses extensive venting in its heavy steel basket to shrug off heat, so you can count on reliable performance.   

Say hello to system flexibility

This Kicker CompR will handle up to 300 watts RMS so make sure you have an amplifier that'll do it justice. Its dual 4-ohm voice coils make it easy to connect to a mono amplifier, and this versatile sub works well in sealed or ported enclosures.

To drive this single subwoofer, we recommend a mono amplifier rated between 225 and 450 watts RMS at 2 ohms. For more information, please refer to our article on How to Match Subwoofers and Amplifiers.

Product Highlights:

  • 8" subwoofer with dual 4-ohm voice coils
  • injection-molded polypropylene cone
  • rubber surround
  • power handling: 100-300 watts RMS (150 watts per coil)
  • peak power handling: 600 watts
  • frequency response: 30-500 Hz
  • sensitivity: 82.8 dB
  • top-mount depth: 4-1/8"
  • sealed box volume: .35 - 1.8 cu. ft.
  • ported box volume: .65 - 1.2 cu. ft.
  • warranty: 1 year
  • Our 60-day money-back guarantee

What's a component sub and why would I want one?

A component sub is simply a speaker that's designed to reproduce bass once it's installed in a compatible enclosure. Think about the impact of a movie soundtrack in a big theater or even in your own home HDTV setup. A component sub can add the same kind of power to the music in your car. And a car sub is not all about the boom that you hear on a street corner (although that's cool too) - you can pair a component sub with your choice of enclosure to get bass just the way you like it, from tight and punchy to fat and loose. And once you experience music in your car with a well-tuned subwoofer, you'll never go back.

Kicker 40CWR84 Reviews

Average Customer Review:

7 reviews
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Written By Anonymous, Alabama on Tuesday, April 14, 2015

Crutchfield Customer Review (What's this?)

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

I put one of these in a ported box with 300 watts rms... It sounds really good and goes very deep for only an 8" sub. It will rival most 10's and 12's easily. Put it in a well built box, and give it plenty of power, and it shouldn't disappoint!

Pros: Bangs like a spring-breaker on a two week bender after her sorority friends left for the evening, easy wiring options with the ohm switch, can handle massive amounts of power for only an 8.

Hummer H3 typhoon replacement

Written By Anonymous, Acworth, GA on Saturday, March 21, 2015

Crutchfield Customer Review (What's this?)

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

Replace factory dolphin Bay speaker number H3

Pros: Sound quality is good

Cons: Replacement speaker Is 2 wore verses 4 wire factory.

Great bass reproduction

Written By Smitty, Mechanicsville, VA on Monday, January 26, 2015

Crutchfield Customer Review (What's this?)

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

This is a well built sub. Heavy voice coils and magnet add to the build quality. Switchable resistance gives many power options. Sounds awesome, gives awsome thump for an 8" sub.

awesome sounding sub

Written By kaleb, Midwest city, ok on Monday, December 29, 2014

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

I've swapped out my system in my truck 4 times in the past 3 years trying to find the sound I wanted. Ive always went with 12" subs... from two old kicker l7's, one alpine type S, 4 kicker compD's.. but these little 8 inch subs are beastly for 8's, i put two in my s10 and they blew my mind after I hooked em up to my Rockford1200.d amp pushing 400 rms watts to them (which btw is what they're rated for, not 300 as they say on this website).. before I bought them I took them out of the box at the stereo shop and was immediately impressed by the quality of the cone, the width of the coil, and how big the magnet was (due to how kickers product quality has declined throughout the years).. the quality is a huge step up from kickers D line of subs. It's no surprise that one of these compr 8's hit harder than a single compd 12...

Pros: -Nice, clear-sounding bass -still hits lows -High power handling -versatile for small vehicles or if you don't want to take up alot of space

Cons: None

Kicker 40CWR84

Written By Anonymous, Annandale, MN on Monday, August 11, 2014

Crutchfield Customer Review (What's this?)

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

Great sound and good price.

Big Little Subwoofers

Written By Chris, AR on Friday, October 04, 2013

Crutchfield Customer Review (What's this?)

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

I bought 4 of these for my chevy silverado crew cab in a quad front fire sealed box. Powered by a kicker zxs1500.1 and they sound absolutely amazing sounds just as good as the 2 12 kicker solo classics I had under my seat down fire and it just looks neat having 4 subs facing forward under the seat. They hit the lows just as good as the 2 12s and they get louder and sound better with all types of music from rap to rock. You can't go wrong with these powerful little subs!

Pros: Great sound, powerful and low distortion

Cons: The terminal caused me to have to turn the subs on an angle due to the box not the subs fault but a con I had with my box I guess.

Kicker Sub-woofers

Written By Frank V, Keller, Texas on Wednesday, August 21, 2013

Crutchfield Customer Review (What's this?)

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

so far, the sound is great and the quality is excellent

Pros: great sound and quality

Cons: none

Hands-on research

What's in the box?

Download owner's manual

  • One 8" Dual 4-ohm voice coil subwoofer (with impedance switch)
  • Kicker logo stickers
  • Manual (English/ Spanish/ German/ French)
  • Template on box

Scratch & Dent items may be missing non-essential accessories. In some cases the manufacturer's accessories have been replaced with generic equivalents.

Product Research


Dual 4-ohm Voice Coils: This woofer features dual 4-ohm voice coils, offering wiring flexibility. A switch on the speaker terminal allows you to easily change from parallel (the woofer presents a 2-ohm load) to series (the woofer presents a 8-ohm load) wiring for the voice coils.

UniPlate Construction: The woofer features a one-piece UniPlate construction with a vented, extended pole piece and backplate. This unique design provides the following benefits:

  • Optimizes heat transfer efficiency for cooler operation
  • Eliminates erratic magnetic flux in the voice coil gap
  • Releases pressure under the suspension for uniform cone movement
  • Prevents the voice coil from bottoming out, and the resulting damage

Tinsel Leads: CompR subwoofers use Spiralead tinsel-lead technology; the tinsel lead wires are woven into the spider to relieve mechanical stress.

Enclosure Compatibility

Sealed Enclosure Applications: Sealed enclosures provide the most control over a woofer and provide accurate sonic reproduction, making them suitable to all types of music. Kicker recommends sealed enclosures in the following range:

  • Minimum Enclosure Volume: 0.4 ft³
  • Maximum Enclosure Volume: 1.8 ft³

Vented Box: Vented (or ported) enclosures typically provide better overall efficiency than sealed so they are suitable for use with smaller amplifiers, giving you more bass output from less power. Kicker recommends ported enclosures in the following range:

  • Minimum Enclosure Volume: 0.8 ft³ with an 8" x 1.5" x 20.75" slot port
  • Maximum Enclosure Volume: 1.2 ft³ with an 8" x 2" x 19.125" slot port

Note: Although smaller than optimal, the prefabricated enclosures we list on the accessory page produce very good results.

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.

Product reviews from the Crutchfield Labs

Kicker's Redline series of amps and subs, which includes the popular CompR and CompRT subwoofers plus their KX amplifiers, gives you the sound and performance you expect from Kicker car audio gear.

What are the Labs?