Whether you’re into four-wheeling, two-wheeling, hot-rodding, or just a leisurely drive, you’ll find no better way to enjoy your music on the road, or off, than with our db, DXi or MM loudspeakers and component systems. These series continue to be the performance standard and all offer the kind of styling that can work in a big-block American classic or a high-tech import.

MM651UM 2 Way Coaxial Speakers

6 1/2-inch coaxial marine loudspeaker

Designed and styled specifically for use in the marine environment, The MM651UM isn’t just car speaker labeled for use on a boat. Used in a speaker can or installed on your boat, it works great for both! A unique tweeter-on-grille design eliminates the traditional tweeter post, resulting in a totally sealed front. With waterproof materials, it will stand up to just about any harsh marine environment while sounding great, thanks to Polk marine certification and Polk  technology.

RRP $279.00 AUD

Product Manual

Completely sealed front design prevents water intrusion.

Built-on grille includes tweeter mount which eliminates the traditional tweeter "stalk".

Sealed crossover assembly is built into back of magnet means there’s no need to find room to hide an extra box.

Stainless steel heavy duty input terminals and mounting hardware will not corrode or tarnish.

Passes the most rigorous 600 hours of salt fog and UV testing (ASTM international B117-03 standard practice for operating salt spray (fog) apparatus and D4329-99 standard.

Dynamic Balance® driver technology for pure, distortion free sound.

Neodymium is a rare earth material we use in all MM driver magnets, excluding 461P, that are about 1/10 the weight of a comparable ceramic magnet and much more powerful.

Carbon composite basket based on the spokes of a wheel is lightweight and will not flex.

Woven glass composite cones feature tremendous stiffness-to mass ratio. Lower mass means faster transients and finer detail.

Klippel optimized components for the best possible performance, even at extreme listening levels.

Marine Certified Polk MM Series speakers are built tough to withstand the toughest environments so they are perfect for use in boats of all types. That’s why Correct Craft offers Polk speakers in their award-winning Nautiques ski and wakeboarding boats.

Large-diameter voice coil (30mm) increases reliability and power handling capacity.

All Polk products are made using the best materials and the most advanced manufacturing techniques. They pass the industry’s most exhaustive quality tests, including drop testing, extreme signal response and UV & salt exposure testing. Polk loudspeakers are built to perform for a lifetime.

Driver Complement

Diameter 1" (2.54cm) 
Type Dynamic Balance weather-resistant silk composite dome 
Mid / Woofer
Diameter 6 1/2" (16.51cm) 
Type Dynamic Balance weather resistant poly-composite cone 


Total Frequency Response 40-25kHz 
Nominal Impedance 4 ohms
Efficiency 92 dB
Power Handling
Continuous 100 watts
Peak 200 watts
Recommended Amplifier Power 15-150 watts per channel


Unit of Measure pair 


Diameter 5 1/16" (12.86cm) 
Full-Range Mounting Depth
Top Mount 2 5/8" (6.67cm) 
Driver Mounting Depth
Bottom Mount 2 7/8" (7.30cm) 
Height 1 1/8" (2.86cm) 


Speaker Warranty 1 year parts and labor (original purchaser)