




The Pair Rockville MS40B 4-inch Marine Boat Speakers deliver powerful, clear audio for boating and outdoor adventures. With 200W peak power (50W RMS), these speakers produce high-fidelity sound, making them ideal for music lovers on the water. Designed for durability, they feature an IP56 waterproof rating, resisting salt, freshwater, and rust, while anti-UV ABS plastic ensures long-lasting performance under harsh sunlight.
These speakers excel in marine environments, ATVs, motorcycles, or cars, offering easy installation with pre-installed screws. Compared to competitors, the MS40B stands out for its compact size, robust build, and balanced sound, solving the need for reliable audio in rugged conditions.
SUPERIOR SOUND QUALITY: Enjoy clear audio with 200W peak power (50W RMS) and a frequency response of 122Hz-20kHz, ideal for music and vocals on the water.
BUILT FOR MARINE ENVIRONMENTS: IP56 waterproof rating ensures complete resistance to salt, freshwater, and rust, with anti-UV ABS plastic for lasting durability.
COMPACT AND EASY TO INSTALL: 4-inch speakers with a 3.66-inch cutout diameter and pre-installed mounting screws fit seamlessly on boats, ATVs, or outdoor setups.
HIGH-QUALITY CONSTRUCTION: Features injection-molded polypropylene cones, aluminum voice coils, and 3.5 oz Y30 ferrite magnets for reliable, distortion-free sound.
VERSATILE OUTDOOR PERFORMANCE: Perfect for marine, car, or motorcycle use, delivering consistent sound in harsh conditions with 85dB sensitivity.
8 reviews for Rockville Pair MS40B 200 Watt Marine Boat Speakers, 4 Inch, 4 Ohm, Waterproof, Compact Design, High-Fidelity Sound, UV-Resistant for Boats and Outdoor Use
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$29.95
Diana Moser –
Happy with the sound quality and price
Great sound while mounted on a motorcycle. Mounted easily, had all the part. Sound quality is clear and loud. Function as they should.
Mr. T –
100% better than OEM
Replaced travel trailer OEM surface mounted speakers. Had to purchase 3 5/8 hole bit to install. Speakers cover existing screw holes so finished installation looked clean. OEM speakers where consider 5 1/2 inch water proof but we’re only 2 inch paper speakers housed in plastic. They were blown when I purchased the trailer new and sounded horrible. These Rockville speakers produce great sound and base compared to OEM and can handle all the volume I threw at them. 100% better.
Just like description perfect –
Best one yet
Love these speakers 🔊 best set i have used yet
Brent Smith –
Not Loud
Bought these 4” speakers to replace 2.5” speakers on my Harley Davidson Softail, also added a 200 watt 2 channel amp. I should have left the 2.5” speakers on, they were much louder. Sound quality is good, but that doesn’t matter if you can’t hear them. Very disappointed. Will be sending them back. Now I have to find a better 4” speaker because I’ve already gone through all the work to mount the new cans and route the wiring. Not dealing with all of that again.
lex Copeland –
Was a wast of time
I did not use that product it was the Rong and did not fit but I keep it for back up sow I could motafy it to fit if I need them
Jrodbooya –
4 inch speakers are 4 inch speakers. They do sound fine to me.
They are 4 inch speakers. Sound a tiny bit better than the factory front 2 that came in my boat. Slightly more bass, I mean there’s not much anyways, and a little more treble in the vocal range. I added these to have all 4 speakers and not just two. Mounted directly in the hollow aluminum gunnels in the factory speaker holes with no special super bass enclosures or anything. Powered by a Sony 55w x 4 stereo- Don’t know the RMS wattage of it but it’s a new Sony 55watt x4. I mean they sound fine to me, they go very loud and don’t distort. I can run my 115 Yamaha outboard at 40 mph and crank up the stereo and hear it. I don’t have subwoofers and all that in there either. For what they are they sound fine to me, they sound like an average newer car factory speaker.
jason a tilghman –
Well worth the money
I added these to my saddlebags and the slim style still allows me to use the bags for loading ….
Dewayne Reid –
Motorcycle Music
Just playing around