We get a lot of calls from sailors and pilots who have a speaker installed in tight quarters near sensitive equipment like a compass or other electronics. The strong magnetic field from the speaker magnet can create havoc! Shielding a compass is not a good idea as it also shields the Earth’s magnetic field.
The Speaker Magnet Shield is designed to attach to the back of the speaker magnet reducing magnetic field emissions by 80-90%. Simple to install. Just place it on the back of the magnet. Magnetic attraction keeps it in place even under moderate vibration. Three layers thick (although the design permits using only one or two layers if desired), corrosion resistant, and only 6.5 ounces. Fits magnets up to 3-1/8 inch diameter. Can also be used to shield other small magnets. Note: The Speaker Magnet Shield can only reduce field strength at the back and sides of the magnet. Because of lack of access, the front of the magnet cannot be shielded. Tools may be required for installation.