Neodymium is an element with specific characteristics that make it particularly well suited for use in speakerconstruction. Speakers operate by using a magnetic field to generate motion in a coil and speaker cone to project an amplified sound signal. In neodymium speakers, the rare-earth element is used as the primary material in the magnets that create the field needed to drive the speaker movement.
The reason that speaker manufacturers explore neodymium as a speaker material is because pound for pound, this element produces the most powerful magnets on the planet. Other magnet types such as alnico and ferrite are often used in speaker construction. It takes a significantly larger amount of either of these elements to create magnets with the same strength as neodymium.
Neodymium speaker magnets are not made from 100 percent neodymium. Usually, the magnets in a neodymium speaker are made up of a combination of neodymium, iron and boron. As a result, they are sometimes referred to as NIB speakers. The term "Neo" is also used to describe a neodymium-iron-boron magnet. The actual chemical makeup of an NIB magnet is Nd2Fe14B.
The strength of neodymium means that the magnets needed for speaker construction are much smaller than those used in other types of speakers. This results in a significant weight reduction in each speaker, something that makes large guitar or bass amplifiers and speaker systems much easier to move, hang or carry. For example, Euphonic Audio manufacturers neodymium speakers that contain magnets that weigh 12.25 pounds less than the magnets used in its CXL-210 speakers. When a single speaker cabinet contains four of those speakers, this means a significant reduction in weight is achieved through the use of neodymium.
Neodymium shows up in a wide variety of speaker types produced by a large range of manufacturers; however, there are some specific applications that it is best suited for. The light weight of the material makes it useful when designing both very large and very small systems. In a very large system, such as speakers that would be used in an outdoor public address system, neodymium magnets prevent the speaker cabinets from becoming weight-prohibitive. In very small speakers, such as high-frequency tweeters, neodymium provides the drive needed to power the speaker while retaining a suitably small footprint.