How do electricity and magnetism produce sound through a speaker?
If we apply a changing electrical signal to the coil, it sets up a changing magnetic field around the coil. This changing magnetic field interacts with the magnetic field of the permanent magnet. The interaction will create a force which will move the coil and cone assembly. It will move the assembly out and in according to the electrical signal. And as the cone moves out and in, it creates a sound wave. The speed at which the cone moves out and in will set the frequency of the sound (the pitch), and the amount the cone moves out and in on each cycle of the signal will set the amplitude of the sound (the volume). That’s it! Really!
