If you’ve never given much thought to the individual components that make up your speakers, you may be confused when you hear the term “speaker driver”. And you may be even more confused when you hear that the speaker driver — not the speaker itself — is what reproduces the sound waves you hear when you listen to music. The “speaker” is the name we use as shorthand for the entire system, which includes not only speaker drivers, but also the circuits that send sounds to the right places, the box that houses everything, and so on.

So, if a speaker driver isn’t a speaker, what is it exactly?

Speaker drivers are the components that actually vibrate to create sound waves — think of them as the engine of your speaker system. Most speakers contain multiple drivers of different sizes, with the largest ones (subwoofers) handling the low bass sounds and the smallest ones (tweeters) taking care of the higher-pitched frequencies

Why do these drivers come in so many different sizes? And how many drivers are “enough” for a high-fidelity audio system? To answer these questions, we should start with why drivers exist in the first place.

What is the purpose of a speaker driver?

The purpose of a speaker driver is to convert the electrical signals produced by your amplifier, headphones, or other music player into physical sound waves that can reach your ear. Without speaker drivers, there would be no sound coming out of your speaker — and no purpose for your sound system to exist at all.

Though the internal mechanics of a wireless speaker or soundbar can seem hopelessly complex, speaker drivers produce sound through a simple series of cause-and-effect. When an electrical signal flows from your music player into the driver, it creates a magnetic field. This magnetic field causes the speaker driver to vibrate back and forth. This back-and-forth vibration creates the sound waves that reach your ears.

In a sense, a speaker driver is a kind of sonic translator. Without it, your music would simply be a series of electrical signals that don’t sound like anything. The driver’s job is first to interpret those signals, then to reproduce them as sound waves. It has several specialized components that work together to make this reproduction possible.

The main components of a speaker driver

It may seem overly technical, but knowing the individual components of a speaker driver can help you visualize how it works. The main parts of a speaker driver include:

• The voice coil, a coiled wire that receives the electrical signal from the music player.
• The magnet, which creates the magnetic forces that power the driver’s movement.
• The diaphragm, a large cone or dome that moves back and forth to create sound waves.
• The suspension system, which surrounds the driver and keeps the voice coil and diaphragm in the correct positions for producing sound.

Types of speaker drivers

High- and low-pitched sounds are different because they are produced by sound waves of different lengths and frequencies. Unfortunately, there's no single driver that can produce the full range of sound waves without distortion, as a driver's shape and physical properties make it more or less capable of reproducing specific frequency ranges, such as low or high sounds.

Different types of speaker drivers exist to handle different sounds, with their capabilities determined mainly by their shape and size. Smaller, lighter drivers can vibrate quickly to reproduce high-frequency sounds, while larger drivers are needed for low frequencies. The names of these different driver types helpfully correspond to the types of sounds they make:

Tweeters

Tweeters are small, usually dome-shaped drivers that reproduce high-frequency sounds (like birds chirping) by vibrating rapidly. Their shape allows them to spread these frequencies evenly across a room, though specialized designs like directional horns can create different spatial effects.

Midrange drivers

Midrange drivers are cone-shaped speakers that bridge the gap between low and high frequencies. Though they can't handle extreme frequencies, they're considered crucial because they reproduce the sounds humans are most sensitive to, including human voices and instruments like the guitar and piano.

Woofers

Woofers are the biggest speaker drivers in an audio system. If you crave deep, rich bass in your audio setup, a subwoofer is your ticket to paradise. These subwoofers often come in their own, separate enclosures, which are roomy enough to properly support and enhance the (physically very long) bass sound waves that a woofer emits.

How many speaker drivers do I need?

As a general rule, the more drivers in a speaker, the more capable it is of faithfully producing sounds across a wide range of frequencies. Additional drivers can also contribute to a spatial audio experience, as different drivers may be positioned to fire sound in different directions, thereby filling the room with immersive sound.

For everyday listening, a speaker like Era 100 has all the drivers you need. It features two angled tweeters to create a crisp and accurate high frequency response and stereo separation, and one midwoofer to handle playback of mid-range vocal frequencies and deep bass.

If a truly immersive spatial audio experience is what you’re after, Era 300 may be a better option. This premium speaker’s design leaves room for four tweeters to cover high and mid-range frequencies — including a forward-firing mid tweeter, two side-firing mid tweeters, and an upward-firing tweeter to reflect sound off the ceiling and produce a height channel. It also has two angled woofers for balanced low-end output.

You can combine Era 300 with a standalone subwoofer like Sub 4 and a soundbar that features even more drivers, all of which contribute to the overall sense of clarity and immersion. In the case of a premium soundbar like Arc Ultra — with its seven tweeters, six midwoofers, and four-motor, dual-membrane woofer — a high number of drivers firing sound in different directions enables innovative spatial audio technologies such as Dolby Atmos.

Clear sound with Sonos is simple

Speaker drivers come in all sizes and a number of different shapes that help - produce sounds across a wide range of frequencies.

A single speaker may house just one driver if it’s part of a multi-speaker system with various specialized components. More versatile speakers, like Era 100 and Era 300, will likely feature several drivers that work together to reproduce and blend different aspects of a song’s sonic profile.

Just remember: Drivers aren’t only responsible for the range of frequencies a speaker can produce, but also for the immersive quality of surround sound. If you’re interested in a speaker that brings you deeper into your music, get in touch with a Sonos expert by phone or chat.