When it comes to waterproof and corrosion proof marine and outdoor speakers poly-planar® continues to set the industry standard as an innovator in technology and design by adding new capability to its comprehensive line. Recognizing that conventional boat audio speakers magnets affect compasses and autopilots, poly-planar® has developed a family of ultra-low magnetic field marine speakers to eliminate the serious problem. Our exclusive new technology allows you to locate boat speakers wherever you want without interfering with your navigation instruments. Reflecting our commitment to excellence, we have incorporated this state-of-the-art technology into the 4000 Series marine speaker, as well as the new MA5500 upgrade boat speaker.