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12 July 2021

How we test wireless, smart and Bluetooth speakers

Discover how our experts test wireless and Bluetooth speakers for sound quality and ease of use. Only the very best earn our Best Buy award.
Oliver Trebilcock
How we test speakers main image - Sonos One SL
How we test speakers main image - Sonos One SL

Whether you're looking for a large speaker with powerful sound or a portable Bluetooth speaker you can easily take around with you, Which? has got you covered with our expert lab tests.

We put every speaker through the same assessments, regardless of brand or price, so you get a completely impartial verdict. Our tests involve a mixture of audio assessments from our professional listening panel, technical lab testing and an ease-of-use analysis. The information we provide is easy to understand and free of external bias (we don’t take sponsorships or advertising), giving you the exact evidence to make an informed buying decision – and avoid being caught out by fake reviews. We don’t beat around the bush – we tell you exactly how it is, and if it’s bad, we say so.

Our reviews answer the most crucial questions about wireless speakers, including:

Click the links above to find out more about how we answer each of these questions in our rigorous tests.

To find out the very best speakers on the market, head straight to our wireless and Bluetooth speaker reviews.

What are Which? Best Buys, Don’t Buys, and Great Value models?

The speakers that impress the most in our tests are made Best Buys. A speaker that scores at least 70% in our professional tests earns our Best Buy recommendation, but you should still read our reviews to check for any factors that might impact your buying decision.

Speakers that receive a poor score of 45% or lower are Don’t Buys and should be avoided – these will have poor sound and so there are far better options for the money.

Great Value models do pretty well in our tests – scoring 60% or more. They're also at least 20% cheaper than the average cost of a Best Buy of a similar design – such as another smart speaker. These are models highlighted by our experts to go for if you're looking for a bargain. Some Great Value models will score well enough to also be Best Buys.

What's the sound quality like?

We connect each speaker to an iPod and put it through a mixture of technical and subjective sound-quality tests. Our expert listening panel is made up of experienced listeners with decades of experience between them, who can discern small differences in sound quality. They also have a range of ages and musical tastes so everything is fully represented.

Our experts listen to and assess contrasting pieces of music covering jazz, classical, pop and rock, and several radio broadcasts, so you can be sure that whatever you listen to, it’ll sound fantastic with a Best Buy speaker. Our rigorous tests leave no stone unturned so you can make sure you avoid being disappointed by an over-hyped product.

How easy is it to use?

We assess each speaker according to a series of typical everyday scenarios, including how easy it is to set-up out of the box and connect to your devices - be it Bluetooth, wi-fi or via a wire. We also look at everyday and advanced functionality, including how clear the instruction manual is and is the controls and any accompanying mobile app is simple to use or not.

For wi-fi speakers we also assess how easy it is to create a multi-room speaker system, and we check the stability of all wireless connections to ensure there are no issues.

What additional features does it have?

If the speaker has any additional features, including sound adjustment controls, music streaming services support or Apple AirPlay and radio functionality, we'll assess them to see how well they work. We also independently test how long the battery on portable speakers lasts on a full charge, so you don’t get caught out by a manufacturer’s over-exaggerated claims.

How long does the battery last?

Many Bluetooth speakers, particularly the ones designed for portability, have batteries built in. Manufacturers will usually give their own battery-life figures, but you shouldn’t take them at their word – our independent tests reveal the claims can vary wildly from the mark.

We leave the speakers running and measure how long it takes for the battery to run down, so you have an exact figure you can trust, and compare to wireless speakers from different brands. Some speakers can't even get near the five-hour mark while others easily exceed 20 – and they’re often nowhere near the manufacturer’s claims in our real-life tests.

At Which? we wouldn’t usually award Best Buys to products that don’t have user-replaceable lithium ion batteries. However, there are currently very few portable speakers that allow you to replace their batteries yourself, so this doesn’t affect our recommendations for speakers with batteries.

Is my personal data secure?

Many speakers are connected to your home wi-fi and the internet. We conduct extensive privacy and security screening on all wi-fi-connected speakers (and their apps) to check for issues that would raise concern. We will alert you in our reviews – and encourage the manufacturer to address the issue – if we find any vulnerability. This testing does not affect the overall score we give a product – however, if we find anything serious, we will make the product a Don’t Buy.

What’s the environmental impact?

A wireless speaker shouldn’t have to be triple-wrapped in non-biodegradable plastic in a box double its size to reach you in pristine condition. We hold manufacturers to account to ensure they’re doing their bit to minimise their impact on the environment. This part of the test does not currently affect the overall score we give each product.

Voice assistants like Alexa and Google Assistant

Some wireless speakers have built-in voice assistants, such as Alexa, Google Assistant, Siri or Bixby, which allow you to control them hands-free with voice commands. These are called smart speakers, such as the Amazon Echo, and there are also a subset of these that also have a large screen, which are known as smart displays, like the Amazon Echo Show.

These devices with voice assistants built-in can perform a vast array of tasks beyond simply music and radio controls – you can also ask them things like the weather forecast or the latest news, or when the local supermarket closes.

Smart speakers and smart displays are still a relatively new concept, and the uses of these products continues to evolve. We conducted a survey in January 2019 of 1919 smart speaker owners and 246 smart display owners, which revealed that the vast majority of owners currently use these products for five main uses:

  • Playing music and radio – 80% of smart speaker owners and 70% of smart display owners
  • Asking quick questions – 63% of smart speaker owners and 61% of smart display owners
  • Checking the weather – 54% of smart speaker owners and 66% of smart display owners
  • Alarm clocks and timers – 40% of smart speaker owners and 54% of smart display owners
  • Searching the internet/services – 13% of smart speaker owners and 30% of smart display owners.

As a result, our current voice assistant testing focusses on assessing the above core functions of these products.

Some people use these products to connect them to products like smart lighting (17% of smart speaker owners and 28% of smart display owners) and other smart home products (9% of smart speaker owners and 20% of smart display owners), but this is currently a minority of users. We intend to regularly re-run this survey to monitor use of these devices and update our testing as these products mature and different uses of them grow in popularity.

Should I buy it?

Every speaker we test gets a Which? test score so you can see which are the best and worst, as well as exactly how each compares to other models. If we detect a fault, we'll buy a replacement to see whether it's a one-off issue, or symptomatic of a larger problem. We'll also speak to manufacturers directly to help remedy any problems that may arise and what they plan to do about the problem.


We use set criteria to determine the overall test score. These are weighted differently depending on whether a wireless speaker is portable or for home use.

Home wireless speaker scores are weighted on the below criteria:

  • 70% sound quality
  • 20% ease of use
  • 10% features

Portable speaker scores are based on the following criteria: 

  • 60% sound quality
  • 25% ease of use
  • 10% battery life
  • 5% features

Home and portable smart speakers (those with built-in voice assistants) are weighted as above, with additional tests for the voice assistants included.

Smart displays, which have a sizeable screen and voice assistant functionality, are scored as:

  • 50% sound quality
  • 20% ease of use
  • 20% quality of display
  • 10% features

If you’re unsure which category a particular speaker is tested according to, click on the top ‘Tech specs’ tab in the review to see what type of speaker it is.

Speakers must score at least 70% to be a Best Buy. Speakers that score 45% or less are highlighted as Don't Buy models to avoid.