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Polk Audio db840
db Series 8" 4-ohm subwoofer
Our take on the Polk Audio db840 by Crutchfield's Dominic DeVito
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
Only had a short time but great speaker for the price.
Ferari, East Wenatchee, WA
What's in the Box:
- One 8" woofer
- 1 Rubber gasket (installed)
- 8 Mounting screws
- Manual (English/Spanish/French)
- Online registration sheet
- 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
Polk Audio db840 Reviews
Average Customer Review(s):
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Features and Specs
|Surround Material||Santoprene rubber|
|Ideal Sealed Box Volume (cubic feet)||0.35|
|Ideal Ported Box Volume (cubic feet)||0.6|
|Port diameter (inches)||3|
|Port length (inches)||11|
|Dual Voice Coil||No|
85 dB at 1 watt
|Frequency Response||30 - 200 Hz|
|RMS Power Range (Watts)||50-180|
|Peak Power Handling (Watts)||360|
|Top Mount Depth (inches)||4|
|Bottom Mount Depth (inches)||4 3/8|
|Cutout Diameter or Length (inches)||7 1/16|
|Parts Warranty||1 Year|
|Labor Warranty||1 Year|
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.
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.
Why did you buy this?
Replacing a back subwoofer in my Lexus SC430. [ Lisa Sep 25, 2016 ]
To install on a new boat. [ Tauris Sep 12, 2016 ]
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 ]
It fits [ Gordon Aug 28, 2016 ]
recommended by Crutchfield. Good reviews. [ darin Jun 21, 2016 ]
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 ]
1 question 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. [ Kenny Feb 23, 2016 ] Staff