Choosing a Digital Audio Player

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Contents

Intro Concepts

A digital audio player is a small, portable device for playing computer files which contain audio data (e.g., MP3 and WMA files). Another general name is MP3 player, because the earliest such devices played only MP3 files and because MP3 is the most prevalent format. The Apple iPod is a well-known brand of digital audio player.

Below is a list of factors to consider if you are shopping for a player. These come from suggestions by !LibriVox volunteers. At the bottom, there are links to other sources of assistance in making your selection. This topic is also discussed in the LibriVox forums, especially those grouped under the heading "Help, Discussion, & Suggestions".

Uses: connections. Consider all the uses to which you want to put the player and, consequently, what jacks those uses will require. For example, do you need line-in or line-out? Some players require an accessory cradle -- at additional cost -- to add those features.

Uses: recording. Do you want to record with your player, such as reading for LibriVox? Some units can do this. If so, then consider the range of sample frequencies and bit rates at which the player can record. Some players can only record with sample frequencies too low for either music or for use at !LibriVox. For the latter purpose, the player should be able to record at the CD standard of 44,100 Hz and at a bit rate of at least 128 Kbps.

Playback bit rates. Players vary in the range of bit rates they can play. For some players, the minimum bit rate is around 32 Kbps. However, 16 Kbps is not uncommon for audio files containing speech which are available on-line (and some are even lower, but that's rare). Some players support bit rates as low as 8 Kbps. And some players are limited at the upper end. According to the documentation for the LAME MP3 encoder, players built on the MAS 3503 chip cannot play files with bit rates over 224 Kbps (the maximum bit rate for MP3 files is 320 Kbps).

File formats. Consider the file formats the player can play, such as AIFF, AAC, MP3, Ogg Vorbis, Wave, Windows Media Audio, and others.

Digital rights management (DRM). Some players do not support DRM (a form of copy protection built into the files). DRM is common in files purchased from on-line music stores.

Filenames. Some players have a limit on the length (ie, number of characters) of the names of files. The result is the player doesn't recognize files with names which exceed the limit. Unfortunately, this is sometimes (often?) not listed in a player's specifications; it is an undocumented limitation.

Song capacity. Be careful to read the fine print regarding a unit's capacity for the number of songs it can hold. In many cases, the stated number is based on Windows Media Audio (WMA) format at 64 Kbps. Music encoded to MP3 format, using a relatively good quality setting, will have bit rates in the range of 180 - 200 Kbps. In this case, the actual capacity will be several times less than advertised.

Playlists. Another convenient feature is playlists. These are a standard type of text file used to create custom lists of audio files to play (the files have the .m3u extension for lists of MP3 files). You can create as many playlists as you choose. For example, the software media player Winamp (MS Windows only) can be used to create playlists of the files on your player if it supports them.

Audio fidelity. This is the qualify of the player's sound reproduction. All devices which play digital music, whether it's the CD player in your stereo system or your digital audio player, have circuitry which converts the digital data into an analog signal before it's sent to the speakers, such as in ear buds or a boombox. This circuitry is called a digital to analog converter, or DAC for short. Converters vary in their design among different devices. A consequence is that the fidelity of the analog audio output they create also varies. These differences in the quality of the sound reproduction can be big enough that they are noticeable, especially if one listens carefully. One of the more popular brands of digital audio players (which shall remain nameless) is said, by audiophiles who have compared brands, to use a mediocre DAC. The practical difference this makes depends on a number of factors: (1) This issue is likely significant only for music, but not for speech (such as audio books). (2) The condition of your hearing. (3) The environment in which you listen -- how much noise is there where you plan to listen most often? (4) The quality of the speakers you'll most often use.


More Help on Picking a Player

Recommendations by LibriVox Volunteers

Reviews by LibriVox Volunteers

Buying Guides

Product Details, User Reviews, and Price Comparisons

Here are useful sources of details about individual players and user reviews, which will tell you both what's good and about whatever warts a particular player may have. Some also include price comparisons from various retailers.

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