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Polk Audio db840

db Series 8" 4-ohm subwoofer

Item # 107DB840

Polk Audio's db Series subwoofers give you trademark Polk performance without stressing your wallet.

Polk Audio's db Series subwoofers give you trademark Polk performance without stressing your wallet.

Discontinued item
1 question - 1 answer

Item # 107DB840

About the Polk Audio db840

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 db840 8" subwoofer boasts a rigid polypropylene cone and durable Santoprene™ surround built to handle big power over the long run. Polk Audio tests their subs rigorously to ensure that they stand up to sunlight, moisture, and extreme temperature changes.

Match a db sub to a suitable enclosure, and enjoy impressive low-frequency performance rarely found in this price range.


Priced per speaker

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Product highlights:

  • 8" 4-ohm subwoofer
  • polypropylene cone with Santoprene rubber surround
  • power range: 50-180 watts RMS
  • 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
  • MFR # AA8401-A

What's in the box:

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

Customer reviews

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Pros:

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Crutchfield response

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Product Research

Features
Enclosure Compatibility

Features

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.

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Customer Q&A

Q
Crutchfield asked: Why did you buy this?
A
Replacing a back subwoofer in my Lexus SC430. [ Lisa  Sep 25, 2016 ]
A
To install on a new boat. [ Tauris  Sep 12, 2016 ]
A
I read reviews of several 8 inch auto subwoofer options after a Google search and this seemed to offer the best fit for my needs, and was attractively priced. I have also had a good experience with polk speakers in the past. [ Ronald  Sep 01, 2016 ]
A
It fits [ Gordon  Aug 28, 2016 ]
A
recommended by Crutchfield. Good reviews. [ darin  Jun 21, 2016 ]
A
Bryce recommendation as a viable drop into a Bose Delco system Bryce's Bio: http://www.crutchfield.com/Support/Bio.aspx?bio=75 [ Brian  Feb 24, 2016 ]
SHOW MORESHOW LESS

1 question already asked

Q
Will this fit in my Door sub's in my 2012 Shaker 500 system mustang?
[ charlie  Feb 23, 2016 ]
1 answer
A
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.
[ Kenny  Feb 23, 2016 ]  Staff

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