Polk MM651UM

Built for the harsh marine climate, the Polk MM651UM 6.5-inch coaxial marine speaker delivers both sound and durability. Polk Audio has a reputation for producing high quality audio equipment, and this speaker definitely upholds that standard; therefore, it receives our TopTenREVIEWS Gold Award. This speaker has it all. It delivers excellent sound quality even at extreme volumes while surviving sea spray and the glaring sun. Pairing a 1-inch silk-dome tweeter with the 6.5-inch mid-range driver creates the best performing marine speaker we reviewed. Add a durable carbon composite basket and waterproof driver cones, and you have a speaker that will last for years.

Polk MM651UM

JL Audio M650

JL Audio MX650

Pioneer TS-MR1640

Wet Sounds XS-650

Wet Sounds XS-65

Kicker KM6200

Rockford Fosgate M262

Infinity 612m

JBL MS 6200

The MM651UM has a 1-inch pure silk-dome tweeter manufactured specifically to vibrate fast enough to produce the frequencies necessary to give your music a more real sound. The highest frequency response is 25,000 hertz, well above the range of human hearing, and this gives your audio a more complete feel to it. On the other end, the lowest frequency response produced by the mid-range is 40 hertz, giving you a decent bass response. Forty hertz is well within the range of a sub-woofer so you could choose to get one, but the speaker does pretty well on its own.

The impedance for this speaker is 4 ohms. The impedance is how resistant the boat speaker is to the current being supplied by the amp or other power source. When purchasing an amp make sure to get one that is rated at 4 ohms to avoid damaging your amp. Matching the impedance will help minimize any problems. The lowest wattage you can run through this speaker is 15 watts, the smallest amount of any speaker on this lineup. You can power your drivers with little power but still have plenty of room to reach the peak 200 watts for the higher frequencies. Because the speaker doesn't have to work very hard, you will get better sound quality.

The crossover assembly in these boat speakers is built in and is sealed against water damage.
The crossover assembly regulates which driver gets the correct frequency, making sure that the mid-range driver isn't doing the job of the tweeter, and vice versa. This means the drivers won't be overworked, and your boat stereo system will work longer.

Polk MM651UM

JL Audio M650

JL Audio MX650

Pioneer TS-MR1640

Wet Sounds XS-650

Wet Sounds XS-65

Kicker KM6200

Rockford Fosgate M262

Infinity 612m

JBL MS 6200

A good marine speaker has to have a certain level of water resistance. The mid-range driver cone, made of a lightweight woven glass composite, seals the front of the speaker and protects the magnet and inner circuitry. The tweeter consists of a silk composite dome and is attached to the grille, eliminating the need for a stalk. This design keeps water and other substances out of your speaker, completely sealing the internal components. The tweeter mount and the grille are separate pieces, so there is the risk that the tweeter could become detached with enough force.

These speakers are designed to be lightweight and durable. The basket where the speaker assembly sits is made of a durable carbon composite material protecting the speakers from water as well as jostling. The material is also very light, adding little weight to the whole assembly. The driver magnet is also made from a lightweight material called Neodymium. The speaker assembly, including the basket, only weighs 8 pounds. The speaker also comes with stainless steel, corrosion-resistant mounting hardware to help keep your speaker looking nice and rust-free.

Polk Audio puts these speakers to the test, simulating sea spray, salt fog and continuous sunlight for 600 hours more severe conditions than these speakers are likely to ever experience. This is not a car speaker pretending to be for marine use. Polk specifically designed these speakers to take whatever your boat can dish out.

Polk MM651UM

JL Audio M650

JL Audio MX650

Pioneer TS-MR1640

Wet Sounds XS-650

Wet Sounds XS-65

Kicker KM6200

Rockford Fosgate M262

Infinity 612m

JBL MS 6200

Polk Audio has an extensive help and support network on its website, including both email support and telephone support, which is important if you prefer one form of communication over the other. They provide both an actual email address and an email form directly on the website, and there's a phone line dedicated solely to technical support.

The FAQs page answers some basic questions including the definition of "Marine Certified" and what makes a speaker coaxial, but what is most impressive is the advice and information articles that are stored directly on the site. There is good information regarding speakers in general and the technologies Polk uses in its speakers.

Lastly, Polk Audio does have a forum and the search option is very thorough. The forums are actively used and well-populated with good advice from others in your same situation. Very quickly you can pull up discussions about installing boat speakers choosing the best marine speakers for your boat.

The Polk Audio MM651UM is the best boat speaker we reviewed. This speaker produces great sound with no distortion at high volumes. The speaker has a good frequency response for a full, complete sound. The unit can be powered at the lowest wattage of any of the speakers on our lineup, and the components are sealed, waterproof and made of materials designed to withstand harsh marine conditions. From stem to stern, these marine speakers are designed to be the best.