How do speakers work? Easily explained

Every day we hear radio and music from various speakers. Most people still know next to nothing about how it works. We explain to you in a simple and understandable way how a loudspeaker is constructed and how it works.

Building a speaker

Almost all loudspeakers basically consist of three different components:

• The coil: A coil is a wound wire through which current flows. The individual turns are isolated from each other so that the current flows through all turns one after the other. This creates an electromagnetic field. One or more such coils are located in the center of a loudspeaker.
• The permanent magnet: A permanent magnet is an ordinary magnet, as we know it from the fridge magnet, for example. It does not need any electrical current to build up its magnetic field. Two such magnets interact with each coil in a loudspeaker.
• The membrane: There is a membrane in each speaker. It consists of either a thin metal or plastic film or a special cardboard. Depending on the design of the loudspeaker, it is connected to the permanent magnet or to the coils.

This is how a loudspeaker works

• First, current impulses reach the loudspeaker via an ordinary cable made of copper wires. They are generated by the device that contains the sound source - that is, by the computer, radio or CD player.
• These current pulses now pass through the coil. This creates electromagnetic waves. Due to the different polarity (north and south poles) of the coil and permanent magnet, either the coil or the magnet is set in motion.
• This causes the membrane, which is either attached to the coil or to the magnet, to vibrate. It pushes the air in front of it and also vibrates it - sound waves are generated.
• If these sound waves get into the ear, our brain converts them into sounds.

In the next article we will explain how a computer works.