Contact us
Close contact box

Polk Audio MM840

Mobile Monitor Series 8" subwoofer

Item # 107MM840

Polk Audio's Mobile Monitor Series subwoofers bring out superior performance from lighter materials, so you'll get...

Polk Audio's Mobile Monitor Series subwoofers bring out superior performance from lighter materials, so you'll get...

Dolly
Need help?
Contact our Virginia-based experts.
Discontinued item

Item # 107MM840

Dolly
Need help?
Contact our Virginia-based experts.

About the Polk Audio MM840

Polk Audio's Mobile Monitor Series subwoofers bring out superior performance from lighter materials, so you'll get the impact you want without the extra weight of a conventional system. Advanced engineering and optimized components reproduce your sound with uncompromising accuracy, for low end that is rich and clear.

Polk Audio's Mobile Monitor Series subwoofers bring out superior performance from lighter materials, so you'll get the impact you want without the extra weight of a conventional system. Advanced engineering and optimized components reproduce your sound with uncompromising accuracy, for low end that is rich and clear.

The MM840 8" 4-ohm subwoofer handles up to 250 watts RMS. A copper voice coil and neodymium magnet motor drive the polymer cone with exceptional efficiency. The carbon composite basket features a "wagon wheel" design that resists flexing during heavy excursion, so your sub hits solidly without distorting.

This sub is certified for marine use, and Polk includes corrosion-resistant stainless steel mounting hardware.


Priced per speaker
READ LESS

Product highlights:

  • 8" 4-ohm subwoofer
  • polymer cone with butyl rubber surround
  • carbon composite basket
  • certified for marine use
  • optional matching grille complements the basket design
  • power range: 100-250 watts RMS
  • peak power handling: 500 watts
  • frequency response: 26-200 Hz
  • sensitivity: 89 dB
  • top-mount depth: 3-15/16"
  • sealed box volume: 0.35 cubic feet
  • warranty: 1 year
  • Our 60-day money-back guarantee
  • MFR # AA3084-A

What's in the box:

  • One 8" subwoofer
  • 1 Foam gasket
  • Eight 1-1/2" Allen head self-tapping screws
  • 8 Speed clips
  • Owner's Manual (English/ French/ Spanish/ German/ Italian/ Portuguese)
  • Online registration sheet

Customer reviews

Loading reviews...

Polk Audio MM840 reviews

Average review:

21 reviews

Thanks for submitting your review

Filter by rating

Customer photos

Sort reviews

Sort by:
Items per page:
View page:

Verified customer (What's this?)
Verified employee purchase (What's this?)

Pros:

Cons:

Crutchfield response

<< >>

Product Research

Features
Enclosure Compatibility

Features

Basket: The MM Series subwoofers use high-tech carbon composite basket structures for light weight and maximum rigidity. They will not rust or flex like stamped steel designs.

Materials: The new polymer woofer cone and butyl rubber surround will not break down over time and will survive the rigors of harsh automotive environments.

Voice Coil: The high temperature, 1-1/2" diameter copper voice coil and polyamide former withstand the most rigorous use while maintaining extremely low distortion.

Terminals: The woofer has heavy duty spring terminals that will accept single banana plugs, pin connectors, and bare wire up to 8 gauge.

Marine Certified: Polk MM Series speakers are built to withstand exposure to moisture and UV rays, so they work well in boats and cars.

Klippel Measurement Technology: State-of-the-art laser based Klippel measurement technology is used to optimize the woofer's motor structure, voice coil alignment, and suspension to improve performance, even at extreme listening levels.

Enclosure Compatibility

Sealed Box Volume: Polk recommends using this woofer in a sealed enclosure; the ideal internal volume is 0.35 cubic feet.

Loading accessories...

Customer Q&A

Q
Crutchfield asked: Why did you buy this?
A
This sub sounds good in my trunk. Gives exactly the bass I was looking for to accompany my rear deck Kenwood 6x9's. Looking forward to receiving and installing my Polk component speakers for the door/kick panels to complete the sound stage. [ Pierre  Jan 02, 2017 ]
A
I chose the Polk Audio Subs because of previous ownership and customer reviews. Literature that Crutchfield provided also helped. [ Gregory  Dec 31, 2016 ]
A
It will replace and fit in the Beats System sub box. Keeping the stock look in my Fiat Abarth [ Michael  Dec 12, 2016 ]
A
Weatherproof and great sounding sub for my jeep [ jason  Oct 04, 2016 ]
A
Have used Polk Audio products in the past and they provide a great speaker at a good value. This subwoofer will be a perfect fit under the seat in our 2003 Sea Ray Sundeck. [ Beth  Jul 19, 2016 ]
A
The Polk Audio name and great Crutchfield price [ Andre  Jun 18, 2016 ]
A
I've had a pair of Polk MM1540's for three years and love them, so when I needed something smaller for the wife's car I chose the 8" version of the same line. The overwhelmingly positive reviews didn't hurt, either. [ CHRIS  Apr 13, 2016 ]
SHOW MORESHOW LESS

Loading articles...

TOP