MagnetShield and Joint-Shield are two absorbtive foils that reduce magnetic interference from speakers. Optimal shielding results from first wrapping speaker drivers with MagnetShield followed by Joint-Shield. A quicker method to shield a device from a speaker is to adhere magnetic shielding foil to the side of the speaker causing the interference. When shielding the back of a speaker cabinet, a MagnetShield plate is needed instead.
MagnetShield is a high-saturation foil that absorbs magnetic fields. While the absorption ability of this material is relatively limited, its high-saturation characteristic allows it to handle large amounts of magnetic energy without becoming worthless. The affordable material is thin enough, at 0.01 inches, to wrap it several times around an object.
Joint-Shield is a highly permeable alloy foil that has a peel-off adhesive on one side. The material is more absorptive than MagnetShield, but it is far more expensive. The material is best adhered to the outermost layer of magnetic shielding on speakers.
An advantage of using these materials is that they do not reduce the sound quality of the speakers, unlike the use of bucking magnets. Magnetometers and digital Gauss meters can be used to test and experiment with the effectiveness of magnetic shielding.