The Complete Handbook of Speakers

Chapter 1: Understanding Speakers

A speaker converts electrical signals—music, speech, alarms, announcements—into sound waves you can hear. That simple statement hides a considerable amount of physics and engineering, but you don't need to understand every detail to make good purchasing and installation decisions. What you do need is a mental model of what speakers actually do, what can go wrong, and why the choices you make in selecting and positioning them matter to real-world performance.

Start with the basic job. An audio source—a phone, microphone, amplifier, receiver, or audio interface—produces an electrical signal that represents sound. That signal is a voltage that changes shape hundreds or thousands of times per second, mimicking the pressure waves that human ears perceive as sound. A speaker's job is to take that signal and use it to move air in patterns that recreate those pressure waves. When you hear music through a speaker, you are hearing the speaker's drivers (the moving parts inside) physically vibrating, pushing and pulling on the air around them, and those vibrations traveling to your ears as sound.

The core component that does this work is the driver. A driver is an electromagnet attached to a moving cone (usually made of paper, plastic, or composite material) or dome (usually made of silk, aluminum, or titanium). When the electrical signal passes through a coil of wire inside the driver's magnet, the signal's voltage creates a magnetic field. That field either attracts or repels the magnet's permanent magnetic field, pushing the cone