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Polk Audio MM5251

400W Max 5.25" 2-Way MM Series Component Loudspeaker System

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• Peak Power: 200W
• RMS Power: 90W
• Woven glass composite cone woofer
• Butyl rubber surround for a smoother response
• 1" Silk/Polymer composite swivel tweeter
• 2-Way crossover with a 2-Position tweeter level

Learn more about the mm5251

We apologize

This item has been discontinued

Description


Polk Audio brand icon

Authorized dealer

Will fit most 6x9" and 5x7"/6x8" locations,
with appropriate speaker adapter. Click "Related Items" Tab.



MM Series - Superior Performance

The Mobile Monitor Series by Polk Audio is the result of 3 years of research and development. The series uses high quality materials and the newest loudspeaker technology to bring the listener an unforgettable experience. The best part about the MM Series is the affordable price. The new MM series have been designed to offer unparalleled sound quality with exceptional fit to meet virtually any application. Borrowing technology from our flagship SR Series, the MM Series offers exceptional value for the price. Through the use of high-tech carbon composite baskets, powerful neodymium motor structures using oversized voice coils, and state-of-the-art woven glass composite cones, Polk Audio offers high-end audio performance normally found only in the most expensive loudspeaker systems. In addition, these space age materials offer weight savings that can mean higher performance for your Car, ATV/UTV or Boat.

General Features:

  • 5-1/4" MM Series - Marine Certified - Component Speakers System
  • Power Handling:
    • Peak: 400 watts per set / 200 watts each side
    • RMS: 180 watts per set / 90 watts each side
  • Woven glass composite cone woofer
  • Butyl rubber surround for a smoother response
  • High-tech carbon composite basket
  • 1" Silk/Polymer composite swivel tweeter
  • Soft dome tweeter
  • 2-Way crossover with a 2-Position tweeter level
  • Klippel optimized components for distortion-free sound
  • 30mm large diameter voice coil
  • Neodymium magnet structure for more power
  • Nominal impedance: 2.7 ohm
  • Frequency Response: 50 - 25,000 Hz
  • Sensitivity: 92dB
  • Top-mount depth (woofer): 2-3/8"
  • Cut-out diameter (woofer): 4-5/8"
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

Priced Per Complete Component System: 2 midwoofers, 2 tweeters and 2 crossover networks.

Check out the Polk Audio MM5251 Owner's Manual

Note: Polk Audio specifies the nominal impedance of these speakers to be 2.7 ohm. The product box states the impedance to be 4 ohm and the speaker magnet shows 2 ohm, this has been confirmed by Polk Audio to be an incorrect specification. The product manual is correct in stating the nominal impedance of the MM series of speakers to be 2.7 ohm.


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Specifications & Details


Speaker Specifications
Series
Polk MM Series
Priced Per
Pair
Number of Speakers
2
Speaker Size
5-1/4"
Design
2-way Component System
Tweeter Design
Dome
Tweeter Size
1"
Tweeter Composition
Silk-Polymer Composite
Woofer Composition
Woven Glass Fiber
Woofer Surround
Butyl Rubber
Peak Power Handling
200 watts
RMS Power Handling
90 watts
Sensitivity
92 dB
Frequency Response
50 - 25000 Hz
Impedance (Per Voice Coil)
2.7
Shallow Mount Installation
No
Top-Mount Depth (Mounting Depth)
2-3/8"
Cutout Dimensions
4-5/8"
General specifications
Speaker Grilles
Yes
Warranty and Return Policy
Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Item Details


Manufacturer:

Model Number:

MM5251

Weight:

5.50lbs

Internal SKU:

mm5251

Internal Product ID:

17949

Customer Ratings & Reviews


Polk Audio MM5251 thumbnail image

5 star
70%
4 star
30%
3 star
0%
2 star
0%
1 star
0%



Durability
4.8
Value
4.6
Features
4.7
Design
4.4
Usability
4.7

Customer Reviews

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Great Value

There are a few better sounding speakers out there, but not many. And nothing even close to this price range. Very clean and crisp sound. You have to get creative with the tweeter mounting, but it's easy for someone with installation experience.

By Ardent1 on October 11, 2010

35 found this helpful


Clean sound

I chose this set over the db series based on the freguency range and Polks reputation for there home monitors. I was taken back by the size of the driver magnet, or the lack thereof. It provides easy fitment in tight spaces. The sound is amazing, capturing sounds that weren't heard on other systems that I've used. One draw back, if your looking for mid bass response, it lacks kick. Of course, that's not really what the mm series were intended for. My listening experience has been enjoyable on the long drive to work, and overall I believe that this is an excellent choice.

By Beatbank on August 14, 2012

33 found this helpful


Good Speaker

I had these polks installed for about 7 months in my audi for the front doors. They are wonderful sounding speakers. Crisp highs that sound great, good mids to fill in the gap, but no lows. Do not think that these make bass. That is wrong. They are for really capturing the upper to mid notes and reproducing them as clean as only these speakers can. No rap or rock song will pound on these. It will just sound clean. I give them a five star on pure sound quality. Polk is a great brand and these prove that.

By Ryan K. on October 24, 2012

30 found this helpful


Amazing sound

I have owned Boston Acoustics, MB Quartz, and Infinity component speakers. The Boston and the Infinity sounded great, but they could not handle power well. This time I decided to try the Polk Audio MM series components, WOW! These speakers sound so good and they have no problem with power. I`m running a Rockford Fosgate Power series 600-4 on my mids and highs with these speakers. They sound so good that I have bought 3 sets to replace all of the speakers in my two vehicles (97 Buick Lesabre and 06 Infiniti G35). I have be into aftermarket stereos for over 20 years and for the price you can`t beat these components.

By gdrakec22 on September 17, 2013

27 found this helpful


Great speakers if you don't have the room for the 6501s!

The MM5251s are awesome speakers, but the slightly larger MM6501s have a much lower frequency response and therefore sound much better.

If you don't have the space, or if you have a sub, then it does not matter!

I know because I have both sets in two different cars.

I highly recommend all Polk MM series speakers for their build quality, design, and warm clear sound.

By johan on October 29, 2009

26 found this helpful


Polk Audio MM5251

I have read other speaker reviews when the writer would speak to "hearing notes and instruments I had not heard before..." Now I know what they're talking about. I haven't even installed my sound processor or amp and my OEM stereo sounds great.

By Mike on September 27, 2009

25 found this helpful


Great Speaker

These speakers sound amazing. They produce great highs and amazing lows and mids. The best speakers I have ever owned! I recommend these speakers to anyone and everyone.

By deckerm45 on January 20, 2010

24 found this helpful


Polk Audio MM5251 Review

I would highly recommend this product.

What I like: The speakers produce accurate and clear music - they sound excellent. The highs are extremely crisp and the mids are strong, but not overwhelming. The sound quality continues into the ear-bleeding intensity levels - I have not yet heard noticeable distortion.

What I don't like: The mounting on the tweeters is not conducive to flush mounting. Neither me nor the stereo installer could find a way to flush mound the tweets, so my truck has them protruding from the dash and it looks terrible. If I had known that they would not flush mount, I would have selected an alternate brand, even through the sound is so good.

By Chris on August 10, 2010

22 found this helpful


Great marine speakers, but only good car speakers

The frequency response, distortion levels, and punch on these speakers are second to none; however, those attributes come at the cost of fidelity. I purchased a set of JBL GTO938 6X9 Speakers, and based on the reviews and relative cost, I expected the MM5251 to blow them away. I was wrong: the 938's reminded me that I purchased marine speakers. If you want maximum sound for your money, get these speakers. HOWEVER, if you're looking for a high quality sound, I recommend you look elsewhere.

By proud2b on December 22, 2011

23 found this helpful


Just go ahead and buy these

I want to say don't go cheap on your speakers, but these really aren't even that expensive. especially for how great they sound. I have these up front and a pair of 90w coaxial polk speakers in the rear powered by a 90w x 4 channel polk amp, with a pioneer deck. and i couldn't be happier with the way it sounds. crystal clear. songs literally sound better with these. I wish i could help to give a more well rounded rating by giving some cons, but i cant think of any. buy these!

By Matt K. on June 14, 2010

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