Why Choose Crutchfield?
Great gear and expert advice
Our experts help you pick the ideal gear for your needs.Meet our advisors
Free tech support for the life of your gear.Read about our one-on-one expert help
You may return items that are complete and like new for any reason within 60 days.See the details of our return policy
Earn one point for every dollar you spend and use those points to save on future purchases.Get full details on Crutchfield Rewards
Deep discounts on car installation gear
We offer vehicle-specific installation instructions, dash kits, wiring harnesses, and speaker accessories at deeply discounted prices with car stereo and speaker purchases. Available for most vehicles.Learn more
Trusted since 1974
Our customers have trusted us with their business, and they’ve helped us win awards for our service.Check out our most recent awards
The manufacturer’s warranty always applies.See more details
6-3/4" 2-way marine speakers
Item # 107MM651M | MFR # AA2652-A
This item is no longer available.
Our take on the Polk MM651UM by Crutchfield's Buck Pomerantz
Polk Audio continues its tradition of making brilliant-sounding speakers in stylishly designed packages their Mobile Monitor (MM) Series Ultra Marine speakers look great and sound even better while meeting the challenges of sun and water to bring you superior sound on your boat.
The Polk MM651UM 6-3/4" marine speakers feature honeycomb-textured woven glass fiber composite woofer cones that resist and suppress unwanted resonances yet respond very quickly for a crisp and powerful sound. Large voice coils over an inch in diameter give the speaker high-power handling capability and extended reliability.
These sealed speakers resist damage from UV rays and salt water, so they'll provide great sound on your vessel for years to come. Each speaker utilizes an extra-small neodymium magnet that saves space and weight, while still delivering a full sound with lots of kick. Their lightweight carbon composite frames provide strong, flex-free support for the speakers' motor assemblies.
The 1" soft dome tweeters add a sweet high end that blends perfectly with the low notes so your music stays in harmonic balance, from the electric bass all the way on up to the cymbals. Stainless steel terminal posts will not corrode or rust, keeping your speaker wires reliably connected.
Note: Polk describes this model as a 6-1/2" speaker. Most manufacturers designate this same frame size as a 6-3/4" speaker. For simplicity's sake, we list it as a 6-3/4" speaker.
These speakers hold up great to the marine enviroment. I'm very impressed with the clear crisp sound they put out. They push the bass better than most speakers of the same cost. I highly recommend these speakers and you will too.
Mick, Dublin, Tx
What's in the Box:
- Two 2-way 6.75" marine speakers with built-in grilles
- 8 Hex-head screws (3mm)
- 8 Speed clips
- Owner's Manual
- Product registration information sheet
- 6-3/4" 2-way speakers (pair)
- woven honeycomb glass fiber composite woofer cone with butyl rubber surround
- 1" soft dome tweeter
- designed and certified for marine use
- stainless steel terminal posts
- 4-ohm impedance
- power range: 15-100 watts RMS (200 watts peak power)
- frequency response: 40-25,000 Hz
- sensitivity: 92 dB
- top-mount depth: 2-5/8"
- warranty: 1 year
- Our 60-day money-back guarantee
Polk MM651UM Reviews
Average Customer Review(s):
Thanks for submitting your review
Features and Specs
|Speaker Size||6 3/4|
|Tweeter Design||1" Soft dome|
|Tweeter Composition||Silk/polymer composite|
|Woofer Composition||Glass Fiber Composite|
|Woofer Surround||Butyl Rubber|
|Parts Warranty||1 Year|
|Labor Warranty||1 Year|
92 dB at 1 watt
|Frequency Response||40 - 25k Hz|
|RMS Power Range (Watts)||15-100|
|Peak Power Handling (Watts)||200|
|Top-mount Depth (Inches)||2 11/16|
|Bottom-mount Depth (Inches)||N/A|
|Cutout Diameter or Length (inches)||5 1/16|
Marine Certified: This Polk MM Series speaker is built to withstand exposure to moisture, salt water, high humidity, UV rays, and a wide temperature range so they work well in a marine environment; such as a boat. The speaker has passed rigorous hours of salt fog and UV testing. The speaker also features a completely sealed front design to prevent water intrusion. In addition, they include stainless mounting hardware for corrosion and rust resistance.
Klippel Optimized Components: Using a state-of-the-art Klippel Distortion Analysis, Polk engineers were able to optimize the woofer's motor structure, voice coil alignment and suspension for the best possible performance, even at extreme listening levels.
Woofer Cones: Woven glass composite cones feature tremendous stiffness-to-mass ratio. Lower mass means faster transients and finer detail.
Butyl Rubber Surrounds: For a smoother response and improved durability, the woofers use butyl rubber surrounds. The airtight rubber surrounds stand up to moisture, sunlight and extreme temperatures while allowing long excursion linear motion and years of reliable use.
Silk/Polymer Composite Tweeters: The 1" liquid-cooled, silk/polymer composite tweeters provide clear, detailed highs.
Neodymium Magnets: The speaker's neodymium magnets offer exceptional strength to performance ratio and is extremely lightweight.
Large Diameter Voice Coils: Large diameter, 30mm voice coils increase the speaker's reliability and power handling capacity.
Carbon Composite Basket: The speaker's carbon composite basket is lightweight and will not flex during music audio peaks.
Built-In Crossovers: A sealed crossover assembly is built into the back of the speaker cover; no need to find room to hide an extra box.
Built-On Grilles: The speaker's built-on grille includes the tweeter mount which eliminates the traditional tweeter stalk.
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?
Though I wanted the option to remove the grill for aesthetic reasons, the fact that this are sealed with internal crossovers made the decision pretty easy. [ Chris Apr 13, 2016 ]
Quality and reputation [ Jeff Apr 08, 2016 ]
Best marine speaker for the money. Don't waste the money on JL. Only wish they came in white. [ Anthony Apr 07, 2016 ]
Read some reviews online and they were excellent, the reviewers consider it a Best buy. The pricing was excellent here so I made the purchase. I usually check ebay before I make a purchase. [ Roy Apr 07, 2016 ]
This speaker was recommended by many other boat stereo enthusiasts on forums such as WakeWorld, Malibu Crew and Team Talk (Mastercraft Owners Forum). It has better power handling and better frequency response than the JL MX650 which is also a highly respected speaker in boat forums. [ Scot Apr 05, 2016 ]