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Polk Audio db840DVC

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

51 Reviews | 5 questions - 10 answers

Item # 107DB840D

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Polk Audio DB 842 DVC



Our take on the Polk Audio db840DVC

Polk Audio's db Series subwoofers give you trademark Polk performance without stressing your wallet. These subs combine high-tech materials with a laser-optimized motor structure for smooth, powerful bass response.

Polk Audio's db Series subwoofers give you trademark Polk performance without stressing your wallet. These subs combine high-tech materials with a laser-optimized motor structure for smooth, powerful bass response.

The db840DVC 8" subwoofer boasts a rigid polypropylene cone and durable Santoprene™ surround built to handle big power over the long haul. The dual 4-ohm voice coils allow you to wire your system to draw maximum power from your mono amp or to safely hook up multiple subs. Match a db sub to a suitable enclosure, and enjoy impressive low-frequency performance rarely found in this price range. And Polk certifies this sub for marine applications, so they're a great choice for your boat too.

Note: If you are wiring this DVC sub for lower impedance, make sure that your amp is compatible. Most car amplifiers are stable down to 2 ohms in standard mode, or 4 ohms in bridged operation.

To drive this subwoofer, we recommend a mono subwoofer amplifier that can put out between 135 and 270 watts RMS at 2 ohms. For more information please refer to our article on How to Match Subwoofers and Amplifiers.

Priced per speaker

The POLK AUDIO DB840DVC is an Excellent replacement for my stock sub woofer.

Steve, PA

What's in the Box:

  • One 8" DVC woofer
  • 1 Rubber gasket (installed)
  • 8 Mounting screws
  • Manual (English/Spanish/French)
  • Online registration sheet

Product Highlights:

  • 8" subwoofer with dual 4-ohm voice coils
  • polypropylene cone with Santoprene rubber surround
  • marine-certified for use in boats and convertibles
  • power range: 50-180 watts RMS (90 watts per coil)
  • peak power handling: 360 watts
  • frequency response: 30-200Hz
  • sensitivity: 85 dB
  • top-mount depth: 4"
  • sealed box volume: 0.35 cu. ft.
  • ported box volume: 0.6 cu. ft.
  • warranty: 1 year
  • Our 60-day money-back guarantee

Polk Audio db840DVC Reviews

Average Customer Review(s):

(51 Reviews)
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Hands-on research

Product Research

Enclosure Compatibility


Dual 4-ohm Voice Coils: This woofer features dual 4-ohm voice coils that offer wiring flexibility. When the voice coils are wired in parallel the woofer presents a 2-ohm load, when wired in series the woofer presents an 8-ohm load.

Polypropylene Cone: The cone is made with polypropylene, which provides durability while being lightweight and rigid. The cone is supported by a vented cone/coil coupler, which stiffens the cone for greater mechanical stability and lower distortion.

Santoprene Surround: The Santoprene surround is resistant to extremes in temperature, humidity, and exposure to sunlight for excellent long term reliability.

NOMEX Spider: The fire-retardant flat NOMEX Spider allows extended linear motion while providing highly reliable mechanical and thermal stability.

Triple-vented Kapton Voice Coil Former: Triple venting of the 4-layer Kapton Voice Coil Former, Cone/Coil Coupler and Pole Piece contribute to the high power handling and reliability of the db Series subs.

Klippel Laser Analyzed: The Polk db woofer's voice coil alignment, motor, and suspension are optimized using a state-of-the-art Klippel laser analyzer for superior cone travel linearity, resulting in a flatter response with lower distortion.

Break-In Period: Polk db subwoofers will achieve even greater performance once they are thoroughly broken-in. To break in a new db Sub, play music through it for 20 to 30 hours at moderate levels.

Enclosure Compatibility

Recommended Sealed Box Volume: Polk recommends mounting this woofer in a sealed enclosure made out of 3/4" MDF with an internal volume of 0.35 cu/ft.

Recommended Ported Box Volume: Polk recommends a ported enclosure made out of 3/4" MDF with an internal volume of 0.60 cu/ft using a 3" diameter x 11" long port.

Recommended Bandpass Box Volume: Polk recommends a bandpass enclosure made of 3/4" MDF with a total internal volume of 0.90 cu/ft. The bandpass box should have a 0.40 cu/ft sealed rear chamber and a 0.50 cu/ft ported front chamber with a 4" diameter x 12" long port.

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.

Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Seemed reasonable. [ Craig  Jun 19, 2016 ]
I needed the mounting holes to match up with my factory woofers in my Pontiac G8 GXP (most nominally 8" woofers would not match, where I could even find the information) and Polk Audio is a brand I have had good experiences with in the past. I did an online chat with Paul, and after he had collected all my measurements of the factory wooofers he recommended these. [ Richard  Jun 17, 2016 ]
Good product for the right price. [ Brian  Jun 05, 2016 ]
To replace a defective subwoofer [ RON  May 20, 2016 ]
GM no longer carries the sub woofer for my Tahoe. So CRUTCHFIELD had the one to replace it. It"s probably a much better SUB than the factory speaker. [ Steve  May 13, 2016 ]
picked this speaker with the help of one of your online staff to match up with my current amp [ Tim  May 08, 2016 ]
I have really enjoyed my Polk Audio for the last 3 1/2 years; so I just decided to make it a complete matching set of speakers in my new car. And when I saw the $20 savings on the sub and it was your top seller, it was a no-brainer! [ Steven  Apr 02, 2016 ]
Replacement for the factory sub in a 2000 Yukon. Closest matching recommended enclosure volume of .36cft factory enclosure, while maintaining the available mounting depth. Recommended at .35. [ Kaylia  Feb 15, 2016 ]
I have Polk marine speakers from Crutchfield throughout my jeep already and it's finally time to replace the last thing, the sub. I wanted it all to match and this is the closest I could figure. [ Warren  Feb 02, 2016 ]
dual coils, high power capability and small size that fits in a box in the back of the Jeep Cherokee. [ Curtis  Jan 29, 2016 ]
Wanted to add some depth to the audio system in my car [ Johnathan  Jan 24, 2016 ]
Came highly recommended by Crutchfield staff and other LS430 owners. [ Christopher  Jan 16, 2016 ]
Not sure what this is but if Cruthfield recommends it, you probly can't live without it! Update, this is the 8 inch sub or better known as the loose hardware sniffer outer! She dumps! [ Kevin  Dec 22, 2015 ]
All based on advisor recommendations [ James  Dec 16, 2015 ]
Needed a woofer for my daughters car to replace the stock speaker that is blown. [ MICHAEL  Dec 15, 2015 ]

5 questions already asked

Yes you can, you wire the two voice coils on the subwoofer in parallel to get a two ohm load. This Polk subwoofer sounds good for us with the GM amp [ Michael  Jul 05, 2016 ]
Yes, the sub has the options to bridge the dual voice coils together for 2 ohm applications. [ Marvin  Jul 05, 2016 ]
The best way to wire you DVC subwoofer to a 2 channel amp is in bridged mode. Most 2 channel amps can be bridged, meaning you'll use the positive output of one channel and the negative output of the second channel. You'll have to follow the instructions that came with your amp to determine which speaker outputs to use for bridged mode. Also, rarely can a 2 channel amp in bridged mode handle less than a 4 ohm load. That means you MUST wire the voice coils of your DVC subwoofer in series. The negative input of one voice coil must be connected to the positive input of the second voice coil. The remaining positive and negative inputs will then be connected to your amp. [ Roman  Jun 24, 2016 ]
yes that is correct [ Kirk  Jun 24, 2016 ]
We have a 2002 suburban with the factory sub. When we purchased the suburban I took it home and noticed the sub surround was completely crumbling apart. This fits the hole and works really well. I did notice the surround rubs the plastic trim cover in front but it has not really affected the performance. Sounds great compared to the previous dead sub. [ Dan  May 02, 2016 ]
worked great in my 01 [ Lance  May 02, 2016 ]
I installed this in my 2002 Tahoe and it worked well with the stock amp. You may have a Bose system in your Yukon and it should still work for you. Hope this helps. [ ROBERT  May 02, 2016 ]
I put one in my 02 tahoe it works well with the factory amp [ kevin  May 02, 2016 ]
It will be a good match for the Rockford Fosgate Prime R250-1. You will want to wire the voice coils in parallel, and you will need to set the gain down slightly on the amp. [ Jeff  Feb 01, 2016 ]  Staff
For 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  May 05, 2014 ]  Staff