Expert Service 1-877-289-7664 [Hours]

Boom. SUBTEMBER is here!

Polk Audio db840DVC

180W 8" db Series Dual 4 ohm Marine Certified Subwoofer

In Stock
|

List price $99.99

$59.95

with warranty

You Save: $40.04 (40.04%)

Arrives by Thursday, Sept. 25 to zip 07095

Add an Extended Warranty

Fast, Free Shipping

Within the US 48

60-Day Money-Back

Hassle Free Returns

Low Price Guarantee

Seen it for less? Click here

365-Day Coverage

Warranty assistance for a year

In Stock

Arrives by Thu, Sept. 25

Get FAST answers from customers ASK a Question See questions answers

The db models have been styled with “tuner” automotive enthusiasts in mind—from the wheel style grilles to the textured driver cones, db says “hot car.” But Polk's db series offers much more than great styling. The full force of Polk Audio’s award-winning engineering went into developing high performance to match the cosmetics. All of the components in the db Series benefit from Polk’s Dynamic Balance technology that stems from a joint research project between Johns Hopkins University's Center for Non Destructive Evaluation and Polk Audio.

The new db Series has been built tough to withstand the rigors of exposure to the sun, water and salt to earn Marine Certified status. db Series speakers are perfect for use in boats of all types.

Product Features

  • 8" Dual 4 ohm db Series Subwoofer
  • Power Handling:
    • Peak: 360 watts
    • RMS: 180 watts
  • Impedance: Dual 4 ohm
  • Black dynamic balance polymer composite cone
  • Santoprene surround
  • Fire-retardant flat NOMEX spider
  • Marine certified
  • 1-1/2" 4-Layer kapton voice coil
  • Frequency response: 30-200 Hz
  • Sensitivity: 85 dB
  • db Series Subwoofer Grill Available
  • 1-year SonicElectronix.com warranty

Product History:

Polk Audio db840DVC thumbnail
(newest, current model)
Polk Audio db804DVC thumbnail
(previous model, replaced by Polk Audio db840DVC)

Subwoofer Specifications

Subwoofer Series
Each subwoofer manufactured is part of a series. This is the name of the subwoofer's series.
db (Polk)
Subwoofer Size
Refers to the diameter of the subwoofer, measured in inches.
8"
Peak Power Handling
Peak power handling refers to the amount of power a speaker can handle during a brief musical burst. The RMS power range figure is a much more reliable rating for determining the speaker's power requirements. The Peak power handling specification is typically rated per speaker unless otherwise noted.
360 watts
RMS Power Handling
The RMS power is the amount of power the speaker requires to operate safely and properly. RMS Power Handling refers to the amount of power a speaker can handle on a continuous basis. We recommend powering your speakers or subwoofer with 80%-120% of its recommended RMS rating. The RMS power handling specification is typically rated per speaker unless otherwise noted.
180 watts
Voice Coil(s)
Dual voice coil subs have more wiring flexibility than single voice coils subs; however, single voice coil subwoofers provide easier hookup options for wiring multiple subwoofers in parallel or series. You may also run a dual voice coil (DVC) sub in parallel, series, or combination. A quad voice coil has four voice coils and is equal to two dual voice coil subwoofers as far as wiring goes.
Dual
Impedance (Per Voice Coil)
The load value (in ohms) that the speakers present to the amplifier per voice coil - the amount of resistance to the current flow. This is a key specification as subs wired in parallel or low impedances can create problems with your amplifier and potentially void all warranties. We encourage you to ask our support department prior to purchase if you do not understand which impedance level will suit your application best.
4 ohms
Voice Coil Diameter
Diameter of voice coil, usually measured in inches.
Frequency Response
The range of frequencies the speaker will reproduce (lowest frequency to the highest). Bigger is better, meaning the wider the range, the better. The optimal range is 20 - 20,000 Hz (which is the range of human hearing).
30 - 200 Hz
Sensitivity
An efficiency or sensitivity rating tells you how effectively a speaker converts power into sound. The higher the number, the more efficient the speaker and the louder it will play with the same input power. An efficient speaker helps you maximize your available power. Most sensitivity ratings measure the speaker's output with 1 watt of input, 1 meter from the speaker. Some speakers' sensitivity is measured with 2.83 volts of input, instead of 1 watt.
 
Efficiency (1w/1m) is not an accurate indicator of a subwoofer's output capability and should not be used as a comparison to other speakers or subwoofers to determine which one is "louder".
85 dB
Xmax (millimeters)
Typically measured in millimeters, the Xmax value is the measure of a speaker cone's maximum excursion in one direction while maintaining a linear behavior.
6.1 mm
Subwoofer Design
This is the design of the subwoofer or the opening of the subwoofer enclosure. Each design has it's own benefits, whether it is a square, circle, or oval.

Round/Circle: This is the typical and common subwoofer design. They have a round cone and are a circle in design.

Square: These woofers are able to achieve a greater cone area in a smaller space. Because of the greater surface area, some square subwoofers will be louder than a round subwoofer of the same size.

Round / Circle
Main Cone Color
This is the color of the speaker's or subwoofer's cone.
Black
Woofer Composition
Lightweight woofer cone materials are essential for efficient operation. Poly cones produce exceptional sound and are sturdy against various changes in temperature. Paper cones are very efficient, and when treated for moisture resistance, will perform at a high level. Poly refers to polypropylene, which is thermoplastic or fibers that are polymers of propylene. IMPP refers to injection molded polypropylene, a commonly used process and material in speakers.
Polymer/Mica Composite
Woofer Surround
A speakers surround is part of the suspension system. The surround protects the cone and prevents it from being displaced as it flexes out from the basket. It is usually made of a durable material like treated foam or rubber in order to withstand the strenuous job of producing bass frequencies.
Santoprene Rubber
Magnet Structure
Defines the overall structure of the subwoofers magnet.
Subwoofer Grille
Most subwoofers are able to accommodate a universal grille; however, some subs include a grille and others have a specific, optional grille available for purchase separately. If "yes", then the subwoofer includes a grille. If "optional (sold separately)" the matching grille will need to be purchased in addition to the sub.
No
Re-Cone Kit Available
Some higher end subwoofers have replaceable cone assemblies. In case of a blown woofer, a recone kit allows for a simple replacement, as opposed to purchasing an entire new subwoofer.
No

Recommended Enclosure Specifications

Recommended Enclosure Type
This is the recommended type of enclosure that the subwoofer should be installed into. Some subwoofers are specially designed for particular enclosures.

Sealed: These enclosures completely enclose the air inside the box. These boxes produce a tight bass.

Ported/Vented: These enclosures have a slot of air to escape from the box. The result is a sound that has more "boom".

Bandpass: These are a combination of both sealed and ported enclosures. They can be very efficient, but require tuning for the best response.

Ported / Vented
Sealed
Optimum Sealed Box Volume
This value indicates the ideal sealed box volume that the manufacturer recommends for the subwoofer. The volume is typically displayed in cubic feet.
Optimum Ported Box Volume
This value indicates the ideal ported box volume that the manufacturer recommends for the subwoofer. The volume is typically displayed in cubic feet.
Top-Mount Depth
The depth when installed on top of the mounting surface. Measured from the bottom of the speaker's magnet to the bottom of the mounting holes on the rim of the speaker.
4"
Cutout Diameter
The actual diameter of the hole you will need to cut out if you are creating a new mounting location for this speaker, or if you are mounting a subwoofer in a box.
7-1/16"
Shallow Mount Installation
This means that the subwoofer/speaker is designed to be installed in areas that do not have a lot of space. Shallow mount subwoofers are typically found under a seat or behind the seat in some trucks.

Shallow mount speakers will typically have a mounting depth of 2" or less, while shallow mount subwoofers will typically have a mounting depth of 3" or less.

No

Electromechanical Parameters

Free-Air Resonance (Fs)
The free-air resonance frequency of the subwoofer, measured in Hz. At this frequency the weight of the moving parts is perfectly balanced with the subwoofers suspension system.
Equivalent Compliance (Vas)
This is the amount of air that has the same stiffness as the subwoofers suspension. The greater the rating, the lower the stiffness and larger recommended enclosure. It is measured in Liters.
Total Speaker Q Value (Qts)
This is the subwoofers relative damping (Q) at the resonance frequency (Fs), including all dimensionless losses. Essentially, a high Qts value (closer to 1.0) means the subwoofer is great for sealed enclosures and a low Qts value (closer to 0) means the woofer is great in vented enclosures. A Qts of around 0.45 means the woofer will work decently in either enclosure type.
Electrical Q Value (Qes)
The subwoofers relative damping (Q) at the resonance frequency (Fs), including electrical losses. Also called the mechanical damping of the subwoofer. The unitless measurement usually varies from 0.5 – 10.
Electrical Resistance of Voice Coil (Re)
Amount of DC resistance of the subwoofer when measured with an ohm meter. Typically, this will read less than the impedance rating of the subwoofer.
Mechanical Q Value (Qms)
This is the subwoofers relative damping (Q) at the resonance frequency (Fs), including mechanical losses. Also called the mechanical damping of the subwoofer. This unitless measurement usually varies from 0.5 – 10.
Efficiency Bandwidth Product (EBP)
This number represents the trade off between having an efficient woofer and one with a wide bandwidth. To calculate this number, take the Fs and divide it by the Qes. If the number is below 50, the woofer is designed for a sealed enclosure only. If it's between 50-100 it can be used in either. Lastly, if it's greater than 100 it's designed for vented enclosures.

Specials with this Item

Promotions
Promotions we have offer More Ways to Shop for items that are on clearance, last chance, special offer and sales, Made in America, and more!

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Sonic Electronix

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
86%
4 Star
7%
3 Star
0%
2 Star
0%
1 Star
7%

Average Attribution Rating

Durability
4.6
Value
4.6
Features
4.6
Design
4.9
Usability
4.9
rollin

Richwood, TX

Overall
Durability
Value
Features
Design
Usability
This sub rocks!!!

March 3, 2014

I just recently put this in my truck and wow this little sub has some kick. Put a small kicker amp on it and its just the right amount of bass for me. great blance with the other polk audio speakers in the truck. If you want a little bass in your ride you cant go wrong with this sub...

0 of 0 found this helpful

Help our customers find the most helpful reviews

Joe Joe

houston, tx

Overall
Durability
Value
Features
Design
Usability
This sub rocks!!!

March 3, 2014

This is a great little sub i put it in a sealed box behind the seat of my truck and couldnt be happier with the punch that comes out of that 8" sub. If your looking for some bass trying to get that full balance of sound in your ride you cant go wrong with this 8" sub.

0 of 0 found this helpful

Help our customers find the most helpful reviews

robert

marietta, GA

Overall
Durability
Value
Features
Design
Usability
So impressed !

April 6, 2012

I have had four systems all having 10s or 12s pushing atleast 500 watts rms per sub.... and I was so impressed with how deep and loud these can hit they are in no way near my Two P3 Rockford 12s but they hit good base notes with out being overwellming. Right now thes 8s are being used with a Kenwood KAC-7205 and they work great to geather in custom sealed boxes in the back of my 300zx z32... I was hopeing for just a little more from these but they are great for the price and well worth buying!

0 of 0 found this helpful

Help our customers find the most helpful reviews

MICHAEL

Pearland, TX

Overall
Durability
Value
Features
Design
Usability
Awesome little sub!!!

March 21, 2012

This little sub doesn't require a lot of power and sounds awesome. I have used this sub in outdoor applications. The latest was a golf cart paired with an MB Quart Marine amp and two Polk Audio 5.25". The setup sounds amazing. I would definitely recommend this sub. It's not over powering but just right and it comes at a great price.

0 of 0 found this helpful

Help our customers find the most helpful reviews

M

YORK

Overall
Durability
Value
Features
Design
Usability
polk audio

September 29, 2011

Great speaker for the price your staff was very helpful.

0 of 0 found this helpful

Help our customers find the most helpful reviews

peter

Weatherford, TX

Overall
Durability
Value
Features
Design
Usability
This item is the perfect solution for most projects

July 31, 2011

This item is very cost effective and has great sound depth and speed. I would choose 8" over 10" or 12" any day because or their performance. Added to that, it is dual voice coil which that in itself makes it better.

0 of 0 found this helpful

Help our customers find the most helpful reviews

JZ20050

Howards Grove, WI.

Overall
Durability
Value
Features
Design
Usability
Good sounding Sub

May 24, 2011

Installed in a VW Golf. sounds great.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Matt

Rancho Cordova, CA

Overall
Durability
Value
Features
Design
Usability
polk 8" subs, incredible mid bass sound

January 3, 2011

used 2 of these subs, one in each door. along with 3 6.5 polk components per door. these provided great midrange and really filled in the frequencies where the subs couldn't hit. Gave them a solid 175 watts rms and they, to this day, take all the power like little champs. order with the matching grills. perfect match to the other polk audio products. and to top it off, no better customer service than that from sonic. thanks guys. will be back. think my wifes stereo needs a redo.....

0 of 0 found this helpful

Help our customers find the most helpful reviews

Douglas766

Clinton Pa.

Overall
Durability
Value
Features
Design
Usability
Nice little sub!

December 30, 2010

Got rid of my 2 ten inch subs and amp to make more room in my hatch. Put this sub in a ported box running off of the factory amp with a passive crossover and after market head unit. Hard to believe an 8 inch is putting out that much sound. I even had to turn the amp down a bit. I'm glad I got it. No wires, but it comes with nice Allen head mounting screws. Great value in my book!

0 of 0 found this helpful

Help our customers find the most helpful reviews

CRAIGnKC

Overland Park, Kansas

Overall
Durability
Value
Features
Design
Usability
Great Replacement

November 8, 2010

Replaced the blown factory sub in my 2006 F-150 with this sub. Had to make a 3/4" spacer ring due to the extra depth this sub required. Other than that fitment was great and sound is better that the factory sub. Should have replaced it years ago!

0 of 0 found this helpful

Help our customers find the most helpful reviews

8upwithit

silver creek ms.

Overall
Durability
Value
Features
Design
Usability
tuff subs

October 7, 2010

I built a box for my 800 can am outlander and put Polk in it. I have never used dual voice coil until now. I must say i am very pleased with these speakers. They have been covered in mud, water, sand and dust and keep on rockin! people can't believe how good this system sounds on the front of an atv! When they die I'll buy another pair just ike them.

0 of 0 found this helpful

Help our customers find the most helpful reviews

will

elk grove, ca

Overall
Durability
Value
Features
Design
Usability
all ready blown

June 3, 2010

I'm powering with an Alpine PDX150. Only 2 channels for 2 speakers and they're blown.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Tom

Charlotte, NC

Overall
Durability
Value
Features
Design
Usability
Great sub for factory replacement

January 7, 2010

Installed this in my wife's '02 SC430 to replace the factory Mark Levinson torn paper cone subwoofer. I added a separate amp to power it and wired the voice coils for single coil operation at 8 Ohms. I was worried at first that the 8 Ohm impedance would not allow enough punch but it is not a problem at all. This sub is efficient and sounds great. Much, much, much better than stock.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Wes

Flint, MI

Overall
Durability
Value
Features
Design
Usability
Great Small Sub

March 14, 2009

Put it in last night to replace my stock subwoofer in my 2006 Lincoln mark LT, this sub sounds a lot better then the old paper cone 8 inch. I had to put a seal around the sub when mounting it to the factory box, i used the foam cut out that came with the subs packing material, it works very good and keeps air in tight. so far i am very happy with it, this is a great sub at a great price if you want to swap out the terrible factory subs cars are coming with now.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Accessory Tools and Products

Accessories added

25 ft. of Streetwires 12 Gauge Speaker Cable

You'll need speaker wire to hook up that new subwoofer!

Your Price $44.95

Belva 23 ft. of 12 Gauge Speaker Wire

Ultra-flexible PVC blended jacket for easy installation.

Your Price $14.99

20 Square Feet of Sound Dampening Material

NVX Sound dampening is thicker than competitors, eliminates rattles and gives you bigger bass!

Your Price $59.99

Dynamat Sound Dampening Trunk Kit

Did you know sound dampening will reduce those annoying rattles and even increase your SPL?

Your Price $109.95

Stinger Sound Dampening Trunk Kit

Stinger's Roadkill sound dampening series is sure to kill unwanted road noise and rattles! Enough sound dampening for your whole trunk!

Your Price $69.99

12 oz. Can of Adhesive Spray

Spray adhesive used for adhering carpet to subwoofer boxes without bubbles.

Your Price $6.99

Spring Post Terminal Cup

Makes adding a spring post terminal to an enclosure simple! Banana clip ready!

Your Price $3.99

40" x 15 Ft Piece of Premium Un-Backed Automotive Trim Carpet

Durable design for long life-span, available in many colors and shades.

Your Price $39.99

Gold Plated Dual Terminal Banana Plug Connector

Enables an expandable, secure connection accepting up to 8 gauge wire.

Your Price $1.99

Car Stereo and Speaker Installation Tool Kit

Includes Test Light, Crimp/Splice Tool, Multi-bit Screwdriver and more.

Your Price $12.99

Xscorpion 9-Piece Nylon Plastic Pry and Chisel Tool Set

Easily removes dash/trims, door clips, panels and pins, rubber grommets and vehicle emblems.

Your Price $14.99

Cordless Multi-Functional Heat Tool Soldering Iron Kit

Continuous working lock allows you to work without holding down trigger.

Your Price $79.99

4 Ft of 1/4" Thick Black Heat Shrink Tubing

Provides abrasion resistance and added protection for your cables.

Your Price $3.99

2" Universal, Professional Heavy Duty Roller for Sound Damping/Dampening

Universal rubber roller to make it easy to install sound dampening.

Your Price $7.99

1mm All Purpose Solder

Solder is all purpose for use on most projects where solder is needed.

Your Price $8.99

Polk Audio DB8G

8" db Series Subwoofer Grille

Your Price $20.99

Scosche SPL Meter

Monitor the noise level of your new car audio system with this SPL meter measuring from 60-135 dB.

Your Price $21.99

Impedance Meter / Signal Generator

Easy to locate tuning frequencies of passive radiators and ported enclosures

Your Price $299.99

1 Polk Audio db840DVC Subwoofer

Mono Amp

2 Channel Amp - Bridged

2 Polk Audio db840DVC Subwoofers

Mono Amp

Mono Amp - Option 1

2 Channel Amp

2 Channel Amp - Bridged

4 Channel Amp - Bridged

3 Polk Audio db840DVC Subwoofers

Mono Amp

4 Channel Amp

4 Polk Audio db840DVC Subwoofers

Mono Amp

2 Channel Amp

2 Channel Amp - Bridged

4 Channel Amp

Items we think you might want
DB1040DVC thumbnail
Polk Audio DB1040DVC

• 540W Peak
• 270W RMS
• Dual 4 Ohm
• Polypropylene Cone
• Santoprene Surround
• Dual Voice Coil
• Fire-retardant Flat NOMEX Spider

Your Price $69.99

Browse 1 question and 2 answers
Hide answersShow all answers | Sort by
Why did you choose this?
Sonic Electronix Store
Exellent replacement for my subwoofer inLexus LS 430
Lyle N on Aug 31, 2014
It will fit in my saddle bag on my Road King replacing the JL subs that are currently in there.
George S on Aug 29, 2014

Product Summary

Manufacturer

Model Number

db840DVC

UPC

747192113773

Weight

8.00lbs

Internal SKU

db840dvc

Internal Product ID

16143

Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: Polk Audio db840DVC