What is a passive speaker and how does it work?

If you're in the market for new audio equipment, there are a lot of options out there, from sleek soundbars to portable Bluetooth® speakers in all shapes and sizes. As you dive into the latest audio tech, you'll likely come across several types of speakers, including “active” and “passive,” and it's important to understand the differences between them so you can select the right stereo speakers for your home.

What is a passive speaker and how do speakers work? In short, unlike active speakers, passive speakers do not have a built-in amplifier. This means they need to be connected to a separate amplifier for operation. There are pros and cons to both types of speakers and you'll need to consider your current audio setup to figure out which option is better for your home.

With that in mind, here's what you should know about passive speakers, how they work and when they're the best solution for your audio needs.

In an audio system, a power amplifier, like the Bose Music Amplifier, plays a crucial role. It receives an input signal from a source – whether it's a computer, mobile device, turntable or microphone – and amplifies it. This amplification process boosts the sound to your desired listening level before transmitting the enlarged signal to the speakers, which then generate the sound waves you hear.

Active speakers, which include portable PA systems and most Bluetooth® speakers, house both the amplifier and speaker in the same unit. Passive speakers on the other hand, must be connected to a separate amplifier. On their own, they lack the capacity to amplify audio input. They also don't have independent volume or EQ controls and in some cases, they may not even have a power cable, as they can use the amp as a power source.

Surround speakers are one common example of passive speakers. These home cinema speaker systems need to be connected to an active speaker, like a soundbar, to project audio into your room. Without a soundbar acting as the “brains” of the operation, the passive speakers wouldn't be able to receive audio from the TV. The same is true about passive subwoofers like the Bose Bass Module 500, as well as large speaker columns commonly used in lecture halls and auditoriums.

While passive speakers do require additional components for operation, there are a number of reasons you might want to integrate them to your sound system. One of the biggest benefits is that passive speakers are designed to be smaller and have lighter speaker enclosures than active models, which makes them easier to install around your home. For instance, the Bose 251® environmental speakers are passive outdoor speakers that you can easily mount and connect to your main audio system.

Passive speakers also feature more customisation options, making it easier to upgrade your sound system down the line. For instance, if you purchase a new amplifier, you can simply move your passive speakers over to the new device. You can also easily expand your audio setup by incorporating extra speakers for high frequencies, subwoofers and other components as you need.

Of course, there are some downsides to passive speakers, too. Passive speakers require more components, which can make them more expensive and take up extra space in your home. Additionally, passive setups are usually more complicated to assemble, sometimes requiring you to run speaker cables between the components. This might require some technical knowledge to ensure your speakers and amplifier are compatible. Passive speakers also aren't portable so they're not a device you can take with you when you leave the house and they generally can't connect to Wi-Fi or Bluetooth.

Passive and active speakers both have their benefits, so it's up to you to decide which option is right for your home. If you're looking for an all-in-one audio solution that's easy to set up, an active speaker is the way to go.

On the other hand, passive speakers might be the better choice if you want to expand your home's audio, add a surround sound system to your living room, or bring music to your outdoor space. Just keep in mind that you will need to invest in an amplifier if you don't have one already.