Magnets are used in speakers to create a magnetic field that interacts with the electrical current in the voice coil of the speaker. As the electrical current in the voice coil changes, it causes the coil to move within the magnetic field, which in turn causes the speaker cone or diaphragm to vibrate and produce sound waves.
There are two main types of magnets that are commonly used in speakers: permanent magnets and electromagnets. Permanent magnets are made from materials that have a naturally occurring magnetic field, and they are used to create a static magnetic field around the voice coil of the speaker. Electromagnets, on the other hand, are made by wrapping a coil of wire around a core material and passing an electrical current through the coil. The current flowing through the wire creates a magnetic field around the electromagnet, which can be turned on and off by controlling the flow of current through the wire.
Both permanent magnets and electromagnets have their own advantages and disadvantages, and the type of magnet used in a particular speaker system will depend on the specific requirements and design constraints of the system.
Neodymium magnets are a type of permanent magnet made from an alloy of neodymium, iron, and boron. They are known for their high magnetic strength and are commonly used in a variety of applications, including speakers, motors, and generators.
There are several reasons why neodymium magnets are often used in speakers:
High magnetic strength: Neodymium magnets have a very high magnetic strength, which allows them to generate a strong magnetic field around the voice coil of the speaker. This strong magnetic field allows the speaker to produce higher sound pressure levels (SPL) and better overall performance.
High energy density: Neodymium magnets have a very high energy density, which means that they can generate a strong magnetic field in a relatively small volume. This is useful in speakers, as it allows the magnet to be made smaller and lighter without sacrificing performance.
High coercive force: Neodymium magnets have a very high coercive force, which means that they are resistant to demagnetization. This makes them less prone to losing their magnetic strength over time, which is important in a speaker system where the magnet may be subjected to repeated high-stress cycles.
Cost-effective: Neodymium magnets are generally less expensive than other types of high-performance magnets, such as samarium-cobalt magnets, which makes them a cost-effective choice for many speaker applications.