MP3 players: How we test MP3 players

Which? exists to give consumers impartial advice, which means that if a product isn't any good we'll say so, without fear of penalty. Which? works for you, providing trustworthy advice without a hidden agenda. Whether you're looking for a MP3 player with great audio quality, a player that supports video playback , or even a player that is easy to use, Which? tests all the scenarios so you don't have to.

We examine everything that matters across all products, including performance, features and how well they work in real life – so you'll know exactly what to expect. Our unique, comparative lab tests mean you can trust our Best Buy and Don't Buy verdicts and choose with confidence. Read on to find out how.

  • What is the sound quality like?
  • What is the ease of use like?
  • What is the battery life like?
  • What is durability like?
  • Maximum volume levels?
  • What is the video quality like?
  • What is the viewing like?
  • Should I buy it?

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What is the sound quality like?

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Our tough lab tests ensure that our Best Buy MP3 players sound fantastic

Five experts listen to several pieces of music on the MP3 players, including Red Hot Chili Peppers' ‘By The Way’, Pink Floyd's ‘Another Brick in the Wall’ and Händel’s Mariengesänge.

The panel checks each MP3 player for any sound flaws such as distortion, poor stereo sound or interfering noises, and describe how the music sounds (balanced, shrill, dull, muffled etc) to give their overall listening impression. 

Tests are carried out using both the supplied headphones and a pair of known high-quality headphones. We also check for sound leakage from the supplied headphones to understand how much, if any, noise escapes to bother people around you. This is known as the ‘Tube test’.

What is the ease of use like?

The usability of MP3 players should be at the top of the charts. MP3 players that score poorly in our trials tend to suffer from a common list of ailments; poor displays, badly arranged keys and long-winded uploading and downloading times when transferring files from your PC to your MP3 player.

Our tests make sure that any below-par MP3 players are weeded out, so you won’t be left hopelessly battling confusing instructions and counterintuitive menu systems or wasting time waiting for files to transfer from your computer.

What is the battery life like?

After we've charged and discharged the batteries several times, we charge the batteries fully, load the MP3 players with 20 tracks and set them playing continuously. We then measure the length of playing time you get from this. 

We then look at the length of time it takes to recharge the MP3 player.

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We rotate all the MP3 players we test in a metal drum to make sure they're built to last

What is durability like?

We place the MP3 players in a drum one at a time and rotate it so that each player falls 50cm about 20 times while playing a playlist of 99 different songs.

After 900 turns of the drum, we rate the players on whether they continue to play music while being bumped about.

This test is particularly challenging for hard-disk players, which have to continually access the hard drive while being jolted.

Maximum volume levels?

Deafness Research UK has found that people who constantly listen to personal music players risk permanent damage to their hearing. We’ve added a test which checks the maximum listening level, to check the possibility of hearing damage caused by extended listening at high volume.

The maximum volume on many MP3 players is 120 decibels, 15 decibels above the limit set by the Health and Safety Executive, which is above the level which can damage hearing.

What is the video quality like?

In addition to this barrage of tests, we also check the video-capable models to asses the quality of their video output. Our experts watch scenes from specific films to check the quality of the display,considering brightness, colour reproduction and if there is any jerkiness to the picture.

We check the screen in four different situations – mild daylight, very bright sunlight and light and dark indoor conditions – so you can expect good viewing wherever you are.

What is the viewing angle like?

MP3 player video

We also check the angle of view, to see whether two people can watch video at the same time, and we give a verdict about how suitable the screen is for watching a full-length video.

Two copies of cartoon feature Shrek are watched to check all this – one is encoded with software supplied with the player, and the other is a high-quality encoding of a DVD using reference software.

Should I buy it?

We give every MP3 player we test a Which? test score so you can see which are the best and worst, as well as exactly how each compares to other models. So what does it mean? Well, the MP3 player score ignores price and is based on our detailed analysed results broken down into the following:

The total test score for music-only models is based on the following weightings:

  • Ease of use 40%
  • Sound quality 20%
  • Battery life 15%
  • Portability 10%
  • Versatility 10%
  • Durability 5%

The total test score for music and video-capable models is based on the following weightings:

  • Ease of use 30%
  • Sound quality 15%
  • Video player 15%
  • Battery life 12%
  • Photo player 8%
  • Portability 8%
  • Versatility 8%
  • Durability 4%

How we test MP3 players

Which? tests around 30 MP3 player a year and we ensure that our guides only have the models that are currently available.

To help you choose the best MP3 players you can buy, we review the full range of products, from lightweight audio-only models for use at the gym to players with large screens that are great for showing videos.

Our expert team designs rigorous and repeatable tests for each and every product we review. For example, when we test our MP3 players for durability, we roll them 25 times in a large rotating metal barrel. This is known as the ‘Tombola test’. Which? tests harder, so you can buy better.

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