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Kicker 40CWRT81

CompRT shallow-mount 8" subwoofer with dual 1-ohm voice coils

11 Reviews | 5 questions - 9 answers

Overview

Our take on the Kicker 40CWRT81

If you're looking for bass for a tight space, Kicker designed their CompRT subs with compact cars, pickup trucks, and even motorcycles in mind. The low-profile 40CWRT81 8” subwoofer performs just like a full-size sub, but without killing all your cargo space. This high-performance CompRT sub stands less than 3" tall, so your installation options are wide open.

A thin sub with big sub bass

If you're looking for bass for a tight space, Kicker designed their CompRT subs with compact cars, pickup trucks, and even motorcycles in mind. The low-profile 40CWRT81 8” subwoofer performs just like a full-size sub, but without killing all your cargo space. This high-performance CompRT sub stands less than 3" tall, so your installation options are wide open.

Kicker 40CWRT81

This sub clocks in at less than 3" deep.

Built with boom in mind

The 40CWRT81 comes equipped with a rigid injection-molded polypropylene cone that won't flex and cause distortion while you're cranking the bass. Its rubber surround will last through years of heavy use, combining with a special-design back and top plate to give you more excursion (which equals more bass) than other skinny subs.   

Made to work with many systems

This sub handles up to 300 watts RMS so make sure you've got a solid amp to power it. You can wire the dual voice coils for either 2- or 1/2-ohm total impedance, giving you more wiring options when setting up your system. This versatile sub sounds great in sealed or ported enclosures.

Important Note: If you are wiring this DVC sub for extremely low impedance, make sure that your amp is compatible. You can damage or destroy your amp by exceeding recommended minimum impedance.

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.

excellent sub great quality

angelo v, New York

What's in the Box:

  • One 8" Dual 1-ohm voice coil subwoofer
  • Kicker logo stickers
  • Manual (English/ Spanish/ German/ French)
  • Template on box

Product Highlights:

  • 8" subwoofer with dual 1-ohm voice coils
  • injection-molded polypropylene cone
  • rubber surround
  • power handling: 300 watts RMS
  • peak power handling: 600 watts
  • frequency response: 30-500 Hz
  • sensitivity: 84.8 dB
  • top-mount depth: 2-5/8"
  • sealed box volume: .20 - 1.25 cu. ft.
  • ported box volume: 1.25 - 1.75 cu. ft.
  • warranty: 1 year
  • Our 60-day money-back guarantee
Reviews

Kicker 40CWRT81 Reviews

Average Customer Review:

11 Reviews

Instant upgrade

Written by: Dave W from Oahu, Hawaii on December 9, 2015

Crutchfield Customer Review (What's this?)

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

I purchased this subwoofer as a direct replacement for the factory subwoofer in my 2001 Chevy Suburban. I have a budget Kenwood deck in the dash and did not change the factory amp. I also chose to wire the sub in series. It made a significant and instant difference in the way my overall system sounds. The bass is focused, unlike the factory which was "blatty", like it was slightly wet cardboard, and inaccurate, if you know what I mean. And I'm sure it will get even better as the speaker breaks in a bit. It's an easy install (just need to drill in screws to the factory box) and a very cheap way to take a decent system and bump it up quite a few notches. **Highly recommend, especially for Subs and Tahoes like mine**

Pros: Price, sound, looks

Cons: None

Kicker 40CWRT81

Written by: angelo v from New York on October 26, 2015

Crutchfield Customer Review (What's this?)

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

excellent sub great quality

Pros: all around a great sub

Cons: not a perfect fit for my 05 Ford Explorer's sub enclosure a bracket would have been helpful.

Good little sub

Written by: Scott S from Mississippi on September 9, 2015

Crutchfield Customer Review (What's this?)

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

Used it as a stock replacement for the sub on a 2015 F150. Required slight modification to the factory box. It took a day or two for it to "break in" but once it did it was a good improvement over the stock subwoofer.

Pros: Good sound and compact fit.

Cons:

Great Suburban/Tahoe Upgrade

Written by: CJ from Springfield, MO on July 14, 2015

Crutchfield Customer Review (What's this?)

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

Paired this sub with a Soundstream STI-700D amp for an upgrade of the factory sub in a 2002 Suburban. (Should be similar for Yukon/Tahoe). Installed this sub in the factory box, in the factory location with zero issues. Had to drill new holes for mounting, but no spacer or other work was required, almost complete drop in. Leveraged the factory sub wiring, and spliced the new amp in near the dash. (See note) . Great sound improvement, and more than satisfies a bass appetite. Also lost no cargo space, and unless you look through the grille and notice the Kicker logo, you'd never know it was upgraded (until you turn it on... then it becomes quite apparent). Note: Amp wires for my vehicle were located behind the glove box. I cut them, and capped the ends coming out of the factory amp. The ends that run thru the vehicle harness I then connected to new amp. Individual amp locations could vary.

Pros: Great Sound Besides mounting holes, drop in replacement for my 2002 Suburban Perfect size for compact install

Cons:

Tight sound out of a little sub

Written by: Tom G from California on June 21, 2015

Crutchfield Customer Review (What's this?)

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

Nice tight sound out of a little sub

Pros: Tight sound

Cons: None

Review on 8" Reduced Depth Sub

Written by: Anonymous from Tulsa, Ok on April 2, 2015

Crutchfield Customer Review (What's this?)

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

Googled Reduced Depth Subs to replace my Stock Sub n my Expedition Limited XL, found great price and easy to order on your site!!

Pros: Fit in without any problems, put small amp to Kicker 8 n sounds 100Xs better than the Stock Sub it replaced...

Cons: Non yet!!!

Replace Stock Sub in Toyota Tundrs

Written by: Anonymous from Texas on December 7, 2014

Crutchfield Customer Review (What's this?)

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

It was one of the best subs for the job, needing a 2 ohm load and having dual 1 ohm voice coils it was a perftic match

Pros: Works great in factory box, I just wanted some extra bass and this Kicker subs fits the bill.

Cons:

2011 Ford Escape (Kicker 40CWRT81)

Written by: Richard from Florida on March 19, 2014

Crutchfield Customer Review (What's this?)

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

I wanted a little crisper sound from my factory system. I have the "Premium" sound package. This made such a huge difference!

Pros: Fits in factory box have to seal hole in back from stock speaker. Very easy install. Works great with factory amp.

Cons: Had to re-drill the mount holes and cut the factory leads.

Kicker 40CWRT81

Written by: steelroller from corinth ms on March 8, 2014

Crutchfield Customer Review (What's this?)

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

Gave it a four on value could've been more expensive or cheaper. I went with one ohm for wiring options. Put it in a single cab s10. Ordered two maybe a little overkill. The stencil was dead on hooked them to a 1500 watt sundown audio amp sound is ridiculous. Great customer service

Pros: Sound quality Wiring options Comes with cutout stencil

Cons: None yet

suburban subwoofer

Written by: ray from Jacksonville, NC on December 20, 2013

Crutchfield Customer Review (What's this?)

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

the price and size was great after going though one other speaker that was suppose to fit in a Factory box. it fit in like a glove...

Pros: it fit in with no modification to the box. the depth was great for a shallow mount speaker. the sound was great.. 10 times better then the factory. the price was great did not break the bank.

Cons: None

Here Comes the Boom

Written by: MikeJ from NC on June 11, 2013

Crutchfield Customer Review (What's this?)

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

Purchased this sub to replace the dead factory sub in my 4Runner. What a HUGE difference it makes! Music that seemed hollow now has rich tones and a real fullness to it. Only complaint is that it didn't quite fit as well as I would have hoped and when really cranked up can vibrate against the plastic cover in the speaker bay.

Pros: Big, rich sound. Great quality.

Cons: Didn't fit as well as I had hoped, although it was VERY close to perfect.

Details

Hands-on research

What's in the box?

Download the Kicker 40CWRT81 manual

  • One 8" Dual 1-ohm voice coil subwoofer
  • Kicker logo stickers
  • Manual (English/ Spanish/ German/ French)
  • Template on box

Product Research

Features

Dual 1-ohm Voice Coils: This woofer features dual 1-ohm voice coils, offering wiring flexibility. When the voice coils are wired in parallel the woofer presents a 1/2-ohm load. When the voice coils are wired in series the woofer presents a 2-ohm load.

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

Enclosure Compatibility

Shallow-Mount: Kicker's CompRT series is designed to minimize depth, giving you subwoofer options where standard enclosures don't fit. The vent-less, solid-pole design allows the woofer to be mounted directly against the rear wall of a sealed enclosure.

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: 0.2 ft³
  • Maximum Enclosure Volume: 1.25 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 a 8" x 1.5" x 20.75" slot port
  • Maximum Enclosure Volume: 1.20 ft³ with a 8" x 2" x 19.125" slot port

Note: Although smaller than optimal, the prefabricated ported 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.

Accessories
Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Compact and powerful, was easy to match to one of Kicker's amps. Should be perfect fit for what I need [ Chad  Mar 03, 2016 ]
With online chat [ kimberly  Feb 22, 2016 ]

5 questions already asked

You can check to see if this will fit your vehicle by using our Outfit My Car tool: http://www.crutchfield.com/car/carselector.aspx For additional details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle. [ Krissy  Feb 05, 2016 ]  Staff
Iam unaware of the article you are talking about but from my knowledge if you wire the amp and sub correctly the 350w rms will be fine for the 300w rms sub just don't over power your gain and bass booster and you should be fine i did own these subs and did like them but i had to go back to a shallow mount 12 for the lower bass. i feel a 10 or 12 is my best choice. good luck [ SEAN  May 14, 2015 ]
SO, dunno how the wiring layout affects the mount, but i would say this, if you're running that kicker in a shallow mount sealed, which i am. Underseat, braced1/2 mdf appx 4x12x22 if mem serves. Driven by a JL 5channel sounds great, the rub. The kicker is the 2nd driver in that box. Its been holding up, the first {cant remember brand) cooked. I am not hitting the kicker with 350, proly not eve 200, so, my advice is do a ported enclosure to use that much power [ Michael  May 14, 2015 ]
You can always turn down the power of an overpowered amp, the reverse is not sure. Good luck! :). [ JEFFRI  May 14, 2015 ]
I forwarded your question to an Advisor and they responded with the following: The Kicker 40CWRT81 subwoofer with dual 1-ohm voice coils would be an appropriate replacement sub for the factory subs in the front doors of the your Mustang. And there are two sets of speaker wires in each door, one set for each voice coil. We don't have an installation wiring harness to plug them into the factory plugs, so you'll need to cut off the factory connectors and splice the vehicle's speaker wires to the new speaker wires. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Jun 05, 2014 ]  Staff
In installed in a Toyota 4Runner so I don't know. [ Susan  Jan 14, 2014 ]
This will depend largely on which factory system you have in your vehicle. For details on installation please contact an Advisor by phone or online chat. They will be able to pull up your vehicle and give you the details on what you will need for an installation. [ Jeff  Jan 13, 2014 ]  Staff
Justin, personally I for two subs, I'd go with the dual 1 ohm for each sub and wire them in a series . This would double the value (ohm) for each. So if you have a dual 1 ohm sub, the amp will see it as a 2 ohm load. Therefor if you have two dual 1 ohm subs (each wired in a series) you could then bridge them so the amp will see a 1ohm load or just wire regular, most newer mono amp bridge internally. Make sure your amp is stable to 1 ohm. Good luck with your install! [ Chris  Mar 05, 2014 ]
Hi Justin. In general you would want to look for an amplifier that would provide about 800 watts RMS. Feel free to contact an Advisor by phone or online chat to discuss exactly which amp will work best for your system and budget. [ Jeff  Dec 11, 2013 ]  Staff
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