With the MP3 format taking the prize for convenience and compression when it comes to music, MP3 players are now a portable-entertainment staple. They let you carry hours of music everywhere you go.

      In this article, you will learn about the technology of MP3 players, the different ways you can use this device, and the various functions you can find on MP3 player models so you'll know what to look for if you're in the market to buy one.

The Mp3 format

      The Mp3 format has completely rewritten the rules of music distribution. And with the growing popularity of MP3 players, it is moving beyond the computer.

      MPEG is the acronym for Moving Picture Experts Group. This group has developed compression systems used for video data. For example, DVD movies, HDTV broadcasts and DSS satellite systems use MPEG compression to fit video and movie data into smaller spaces. The MPEG compression system includes a subsystem to compress sound, called MPEG Audio Layer-3. We know it by its abbreviation, MP3.

      The MP3 format is a compression system for music. This format helps to reduce the number of bytes in a song, without hurting the quality of the song's sound. The goal of the MP3 format is to compress a CD-quality song by a factor of 10 to 14, without losing the CD sound quality. A 32-megabyte (MB) song on a CD compresses down to about 3 MB on MP3. This lets you download a song in minutes rather than hours, and you can store 10 to 20 songs on an MP3 player using a relatively small amount of memory.

Taking your Mp3 files with you
      Many people who start collecting MP3 files find that they want to listen to them in all kinds of places. Small, portable MP3 players answer this demand. These players are like portable cassette or CD players, except that they are smaller and they use solid state memory instead of a physical medium like a tape or a CD. All of the players currently on the market include a software application that lets you transfer your MP3 files into the player. Most of them also include utilities for copying music from CDs or Web sites, and the ability to create custom playlists.

      The MP3 player is a wonderful example of a new use of existing technologies. None of the components in a typical MP3 player is radical, or even new, technology. By simply combining these components in a new way, and writing some code to control it all, manufacturers have created an entirely new line of consumer products!

The job of the MP3 player is pretty straightforward. When you play a song, the player must:

1. Pull the song from memory byte by byte

2. Decompress the MP3 encoding

3. Run the decompressed bytes through a digital-to-analog converter

4. Amplify the analog signal so you can hear it

      The main difference between a portable CD player and an MP3 player is that the CD contains the bytes instead of memory, and on a CD the bytes are already decompressed so no decompression is needed.

 

Part of a Mp3 player:

Let's take a look at the components that make up a typical MP3 player:

• Data port

• Memory  

• Microprocessor 

• Digital signal processor (DSP)

• Display

• Playback controls

• Audio port

• Amplifier

• Power supply

      The player plugs into your computer's USB port, FireWire port or parallel port to transfer data. USB-based players transfer data many times faster than those that use the parallel port. The MP3 files are saved in the player's memory.

Memory types include:

1. Internal Flash memory

2. CompactFlash cards

3. SmartMedia cards

4. Memory Stick

5. Internal microdrive

      With the exception of the last one, these are all types of solid state memory. The advantage to solid state memory is that there are no moving parts; and no moving parts means better reliability and no skips in the music.

      The microprocessor is the brains of the player. It monitors user input through the playback controls, displays information about the current song on the LCD panel and sends directions to the DSP chip that tells it exactly how to process the audio.

      The DSP pulls the song data from memory, applies any special effects, or EQ, and streams it to the amplifier. The DSP runs a decompression algorithm that undoes the compression of the MP3 file and then a digital-to-analog converter turns the bytes back into waves (see How Analog and Digital Recording Works for details).

      The amplifier boosts the strength of the signal and sends it to the audio port, where a pair of headphones or ear buds are connected.

All of the portable MP3 players are battery-powered. Most use one or two AA batteries and last for approximately 10 to 12 hours on a single charge. Many of the players also have AC adapters so they can be plugged into a normal electrical outlet, and some even offer DC adapters for use in a car.

MP3 players that contain tiny hard disk drives can store 10 to 150 times more than Flash memory devices can.

Player Function

      The MP3 format is a compression system for digital music that helps reduce the size of a digitized song without hurting the sound quality. Digital music is converted to MP3 format and made available for individual use, usually on the Web. 

      You can download MP3 files from the Internet using your computer and special software, either commercial or freeware.

      You can also convert digital music from a CD into MP3 format using your computer and commercial or free software.

      You can play MP3 files in three different ways:

• You can play them directly on a personal computer

• You can decompress an MP3 file and record it onto a CD

• You can play MP3 files on a portable MP3 player. (Note: here we are referring to "MP3 player" as the device, rather than the software used to play the MP3 file on a desktop or laptop computer.)

      The advantage of MP3 players is that they are small, lightweight and rugged. They are a great way to carry your MP3 files with you!

What Can You Do with an MP3 Player?
With a portable MP3 player, a personal computer, and the appropriate software, you can do the following:

• Obtain free or low-cost music from the Web

• Create your own mix of music (download MP3 files from Web, convert tracks from CDs)

• Listen to near-CD quality music wherever you go

• Listen to more music (up to 10 hours' worth)

      The easiest way to obtain songs in MP3 format is to find them on the Web. See How MP3 Files Work for details on downloading and listening to MP3 files.

      In the next section, we'll talk about the process of ripping songs from your CDs and downloading them into the player.

Converting and Downloading Files
If you have a CD collection, and would like to convert songs from your CDs into MP3 files, you can use ripper and encoder software. A ripper copies a song's file from the CD onto your hard disk. The encoder compresses the song into the MP3 format. By encoding songs, you can play them on your computer or take them with you on your MP3 player. The ripper and encoder software may come with your MP3 player. The specific instructions will vary with the individual software programs, but the following steps will definitely take place:

• Place the CD from which you want to convert songs into your drive.

• Select the track(s) that you want to convert to MP3 format.

• Convert the selected track(s).

• Copy the new MP3 files on to your computer's hard disk.

See How MP3 Files Work for details.

      Now you are ready to download these MP3 files into your portable MP3 player.

Downloading MP3 Files to an MP3 Player
Once you have MP3 files on your computer, you can use the software that came with your MP3 player to download the files into your MP3 player. Again, the specific instructions will vary depending upon your software program and player, but you will:

• Create a playlist from your MP3 files.

• Plug the player into your computer's parallel or USB port (depending on the features of your player).

• Transfer the MP3 files according to the instructions.

The process only takes a few minutes!

Using an MP3 Player
      Once you have downloaded the MP3 files into your portable MP3 player, you are ready to take your music anywhere. Most MP3 players are small (3 in x 5 in / 7.5 cm x 11.5 cm, or less), lightweight, and solid-state. Because most players are solid-state, there are no moving parts to break down or skip, so the sound quality is uninterrupted regardless of your physical activity. MP3 players are equipped with various types of headphones or earpieces.

      Portable MP3 players can play music longer than a portable CD player. The length of play for a CD player is about 74 minutes, the length of one CD. However, the length of play for an MP3 player depends upon its memory capacity, which can be upgraded on some models. A standard MP3 player can play for about half an hour (32 MB) to a few weeks (40 GB)! Some models can be upgraded with additional memory devices.

      Next, we'll talk about some other features you can find in MP3 players.

Features
      When you're picking out your MP3 player, you should pay attention to the following features (in addition to the usual considerations like size, weight, durability, price, etc.):

• Type of connection (USB, FireWire or parallel)

• Memory amount

• Memory type

• Operating system support - Make sure the player supports the operating system you have on your computer, or else you won't be able to do much with it.

Memory

     The MP3 files are saved in the player's memory. Most models are equipped with anywhere from 32 megabytes (MB) to 60 gigabytes (GB). Memory can be upgraded in some models. The type of memory in MP3 players is either totally internal, totally removable, or some combination of the two (optional on some models). Memory types include:

• Internal Flash memory

• CompactFlash cards

• SmartMedia cards

• Memory Stick

• Internal microdrive

      With the exception of the last one, these are all types of solid state memory. The advantage to solid state memory is that there are no moving parts, and no moving parts means no skips in the music and better reliability.

      The advantage of the MP3 players equipped with a microdrive is a huge song capacity. A microdrive is basically a miniature hard disk, like you find in a desktop or laptop computer. A hard disk can have anywhere from 300 megabytes to 60 gigabytes of space -- enough to hold weeks of music!