MP3 player reviews: How we test
We listen to music on each MP3 player
MP3 player sound quality
We expect high standards of sound quality from the best MP3 players and MP4 players and use music from a spectrum of genres (including pop, rock and classical) to test their ability to play music clearly.
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.
We also listen to built-in speakers where present and our experts rate these, bearing in mind the kind of quality you can expect from such small non-stereo speakers.
Ease of use
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 don’t have to be left hopelessly battling confusing instructions, counterintuitive menu systems, or wasting time waiting for files to transfer from your computer.
For instance, we time how long it takes to upload and download a set of 100MB music files, which is about the length of a couple of average digital albums. Not surprisingly, times vary significantly between players.
For example, the iPod Nano takes a sprightly 11 seconds, but the sluggish Dolphin Nu took more than 190 seconds.
Aspects such as the quality of the controls and menus, the quality of the display, the comfort of the headphones, and the portability of the player are also taken into consideration.
MP3 player battery life
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.
We test each MP3 player in a tumbler
Durability
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
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.
MP4 players
In addition to this barrage of tests, our MP4 players are also examined for the quality of their video output. Our experts watch scenes from Shrek to check the quality of the MP4 player’s displays, 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.
Viewing angle
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.
Additional features
A few players can also record from TV. For these we check the ease of use and the quality of a recording of the Robin Williams film Jumanji.
If any MP4 players can show videos via TV, we also look into the quality of this, checking if the image fills the entire screen and if you can choose the correct aspect ratio, such as widescreen or 4:3.