It’s easy to take the technology that powers our wireless speakers for granted. But it wasn’t that long ago that wired speakers were the norm, and listening to music meant being tethered to a specific room in your home. Now that wireless technologies like Bluetooth and WiFi have transformed how we listen to audio, it’s worth digging deeper to learn how these different connection methods work.

This isn’t just about satisfying your curiosity about devices you probably use every day. Understanding how different wireless speakers work can help you choose the best speaker for your needs and listening habits. It can also reveal why certain speakers perform better in different environments and use cases.

How do speakers generally work?

Speakers of all types work by converting electrical energy into sound waves through electromagnetism.

In this guide, we'll start with a general review of speaker functionality before focusing on the two technologies behind most of the wireless speakers you'll encounter: Bluetooth and WiFi. While it may seem complex, the basic process can be broken down into five simple steps:

First, an audio-playing device (like a phone or speaker amplifier) transmits an electrical audio signal to the speaker.

• This electrical signal travels through a voice coil—a coil of wire positioned inside a magnetic field created by a fixed magnet inside the speaker.
• When electricity flows through the voice coil, it creates a magnetic field that interacts with the fixed magnet’s field. This interaction causes the voice coil to move back and forth rapidly.
• As it moves, the voice coil vibrates the speaker’s diaphragm. The diaphragm is a lightweight speaker component that’s usually cone or dome-shaped, allowing it to displace air and create pressure waves as it vibrates.
• These pressure waves travel from the speaker to our ears, and we hear them as music (or as our favourite podcast).

These basic mechanics are the same in every type of speaker, from the ancient wired speakers in your parents’ setup to the wireless WiFi and Bluetooth speakers of today. However, other aspects of speaker technology have evolved and improved over time. For example, modern speakers often use digital-to-analogue converters (DACs) to process audio signals from digital sources—which simply wasn’t necessary before the advent of digital audio files.

It’s also worth mentioning that, when we talk about a speaker today, we’re often talking about a speaker enclosure that contains multiple different types of speakers designed to produce specific frequencies of sound. For example Arc Ultra is powered by 14 Sonos-engineered speakers, including tweeters that create crisp high frequencies and a woofer to deliver exceptional bass.

How do Bluetooth speakers work?

A Bluetooth speaker produces soundwaves just like any other speaker. The key difference is in how the audio signal gets from the source device (like a phone or laptop) to the speaker itself.

Bluetooth technology creates a wireless connection between a source device and a speaker using short-range radio waves. For a device to connect with a speaker over Bluetooth, both devices must be Bluetooth-compatible. When you enable Bluetooth on both devices and switch on ‘pairing’ mode, they can use radio waves to discover each other (you may need to enter a PIN or code to establish a secure connection).

Once paired, the source device transmits audio data wirelessly to the speaker. This process uses codecs—algorithms that compress and decompress audio data for wireless transmission—to send the audio information more efficiently. The speaker receives these compressed signals and converts them back into analogue audio signals. From here, a Bluetooth speaker works like any other speaker, creating sound waves that ultimately reach your ears as music.

Because Bluetooth uses a one-to-one connection over radio waves, it doesn’t require an internet connection. This makes Bluetooth especially convenient for portable listening.

Bluetooth speakers can generally deliver high-quality sound, though the compression process may slightly degrade the quality of certain audio files.

How do WiFi speakers work?

Another type of wireless speaker, WiFi speakers transmit audio signals over a wireless internet network—like the one you have in your home, office or secret mountain lair.

Unlike Bluetooth speakers, which create a direct device-to-speaker connection, WiFi speakers connect to an existing WiFi network. This provides a more stable connection with broader bandwidth, allowing them to stream lossless audio without codec limitations. To connect, both the device and speaker must be on the same WiFi network.

WiFi speakers do especially well in multi-speaker setups, and they’re an ideal choice if you’re building a home sound system, like a home theatre or a multi-room audio setup. In a typical surround sound setup, wireless speakers connected to the same network are positioned at the front, rear and sides of the listening position. Some speakers and premium soundbars, like Arc Ultra, use Dolby Atmos technology to deliver multiple audio channels from the same speaker enclosure. This means that you can achieve an immersive spatial audio listening experience with fewer speakers than you might expect.

With a solid WiFi connection, most WiFi speakers can stream high-quality audio via music services like Apple Music or Amazon Music HD without sacrificing sound quality. Their multi-speaker compatibility gives them an advantage over Bluetooth for comprehensive audio systems. Conveniently, some portable speakers like Sonos Move 2 support both technologies, so you aren’t forced to choose.

How are wireless speakers powered?

There’s no getting around this one: Wireless speakers must be charged or connected to a power socket.

Fully charged portable speakers typically have a battery life ranging from a few hours to up to 24 hours, depending on the size of the speaker and battery. For example, Move 2 can last up to 24 hours, while the super-portable Roam 2 gets you around 10 hours of non-stop playback.

When it comes to wireless speakers used in the home, the distinction between active and passive speakers is important to note. An active speaker, also known as a powered speaker, contains a built-in amplifier and thus does not require an external amp as a source of power. A passive speaker, on the other hand, must be connected to an amplifier, which in turn must be plugged into an electric source.

If your speaker plugs directly into an electric source, it’s probably an active speaker. Most Sonos speakers are active, though our in-wall, in-ceiling and architectural speakers are passive.

Get speakers that sound great every time

Sonos makes it easy to listen to high-quality audio wherever you are, regardless of whether you’re connecting via Bluetooth or WiFi. Now that you know the difference between these two technologies, you can choose the speaker (or multi-speaker setup) that suits you best.

For more on the relative pros and cons of each technology, check out our guide to the key differences between Bluetooth and WiFi speakers.