How does a loudspeaker use a current-carrying coil and a magnet to create sound?

A loudspeaker functions as an electromechanical transducer that converts electrical energy into sound. Most common designs are electromagnetic, or dynamic, speakers that utilize a voice coil positioned within the magnetic field of a permanent magnet.1

The process works as follows:

• Current Interaction: When a time-varying electric current—representing an audio signal—flows through the voice coil, it creates a fluctuating magnetic field that interacts with the field of the permanent magnet.1
• Mechanical Motion: This interaction exerts a force on the coil, causing it to move back and forth within the magnet's gap.1
• Sound Production: The voice coil is attached to a diaphragm (or cone). As the coil moves, it vibrates the diaphragm, which in turn pushes and pulls the surrounding air to create pressure waves that we perceive as sound.21

This mechanism relies on the precise suspension of the coil to ensure rapid response and accurate reproduction of the original signal.1