Magnetism: Loudspeakers

Magnetism: Loudspeakers

  • Loudspeakers rely on the principles of magnetism to function. They use an electromagnet to create sound.

  • A key component in this process is the coil of wire, which works as an electromagnet when electric current is passed through it.

  • The moving coil, attached to the speaker cone, is placed inside a permanent magnet.

  • As electricity (sound signal) passes through the coil, it generates a magnetic field within it. This interacts with the magnetic field of the permanent magnet.

  • These interactions cause the coil, and therefore the speaker cone, to vibrate. These vibrations produce sound waves that we hear as music or speech.

  • The amplitude, or volume, of the sound is directly linked to the amount of current passed through the coil. More current results in stronger magnetic fields, leading to larger vibrations and louder sound.

  • The pitch of the sound relies on the frequency of the electric current. Higher frequency results in higher pitch, and low frequency results in low pitch.

  • In summary, loudspeakers convert electrical energy into kinetic energy (movement of coil and speaker cone), and then into sound energy.

  • Knowing the principles of magnetism and how they are applied in real-world objects like a loudspeaker can help you understand and appreciate the physics behind everyday items.