Almost all computer devices have at least one small speaker, even if it is just there to “beep” when an error occurs! A speaker converts an electrical signal (digital) to a sound wave (analog).
In this post:
Required knowledge:


1. Construction

A speaker consists of:
- a speaker cone, or diaphragm
- a voice coil
- a magnet
The speaker itself is often built into a speaker box which offers additional acoustic amplification.
Headphones are designed to be worn on a user’s head so that a small speaker is held in place over each ear.
2. How it works
- An amplifier sends a signal to the speaker’s terminals.
- The current flows through the coil of wire, suspended in the circular gap between the magnet poles.
- The coil moves back and forth inside the magnetic field as the current alternates direction with the applied signal.
- The centre of the speaker cone, attached to the coil, gets driven back and forth.
- As the cone moves, it pushes and pulls the surrounding air, creating pressure waves—sound!
3. Practical
Take an old speaker from a computer and attach a piece of copper wire to each terminal. Hold one wire on the positive terminal of a 9V battery and tap the other on the negative terminal.
References:
- Harris, O., SoundScapeHQ. (2023) How Do Speakers Work? A Guide To Components, Working Principle, And Troubleshooting. Available at: https://soundscapehq.com/how-do-speakers-work/ (Accessed: 7 July 2024).