MP3 uses perceptual audio coding and psychoacoustic compression to remove all unneeded, redundant or irrelevant information that the human ear cannot hear. This allows you to squeeze the CD contents by a factor of 12 without sacrificing sound quality (at least for most of us).

We can compress it even more by choosing a smaller bitrate to achieve a particular sound quality and obtain a directly corresponding reduction ratio. Some of the portable devices use a fairly low bitrate so that they can claim to hold more music. The table below shows the common settings with the most interesting information being the size in the last column. This is the size of one minute of sound.

The downside of MP3 is that it uses lossy compression, a data compression technique in which some amount of data is lost. If you were to compare an uncompressed file with the original file, they would not be identical. At least in theory, the lost data is redundant or unnecessary. If the MP3 used lossless compression (like ZIP), it would only compress the files by a factor of about 2:1 instead of 12:1.

In most songs you will never notice the loss of any information. If you do, it is possible to change some settings and record that song with less compression.

Most encoders use constant-bitrate (CBR) encoding. In this mode you choose a target bitrate (say 128kbit/s) and the encoder will hit it. Three different stereo modes are available for encoding stereo files:

• Intensity stereo - Mono recording with direction information to create a stereo effect.
• Joint stereo - Uses intensity mode for low frequency information and discrete channels for high frequency information. Some encoders can 'share' unused bandwidth between channels.
• Dual mono - Encodes each channel completely separately.

Some encoders also include variable-bitrate (VBR) capabilities. This uses an index to determine if enough signal has been encoded to meet quality requirements. The index is a number like 50, 75 or 90. The bitrate can be as low as 32kBit/s and as high as necessary—usually averaging 110-140kBit/s in normal mode. The Joint stereo method of encoding is used.

For CD quality, 128 kbps sampling seems to be the best choice. If you do not care about the larger file size, you can oversample with 160 kbps. Most of the portable players will downsample as needed to allow the songs to be loaded.

CBR encoding will provide the best encoding for most music. The jury is still out on the value of VBR encoding. It should result in the best quality sound at the minimally required space. Check to see if your playing device can use files created with VBR before you encode your library this way.

It is recommended that you let the encoder place the files in a separate directory for each album. In addition, choose the option that places the track number in the filename. Otherwise, it may be difficult to play the songs in the album's original order without manually selecting the song order.

You can either get music in an MP3 format that someone else has created or you can make your own.

The Internet holds a lot of MP3 files, but most of these files are illegal. There are some files placed there legitimately by their owners. Those are obvious; you can tell the legal from the illegal. www.MP3.com tries to get around the legal aspects by requiring that you prove you own the CD you want to download an MP3 version of. The theory is that you can download the file faster than you can create the file. With today's software, that may no longer be true.

Currently available software can convert an album to MP3 in about a quarter of the playing time and cost you nothing. Register that software and get even faster conversion. The whole process of ripping the music from the CD, titling the songs, and compressing the music is quick and painless.

There are lots of options when it comes to MP3 players. There are lots of MP3 player programs, including software that lets you play MP3s on your Palm or Pocket PC. There is a multitude of portable MP3 players. The latest technology is MP3 CD players.

There is not enough time to cover all of the MP3 player software—the list seems to grow daily. We will limit our discussion to the leading software: WinAmp, MusicMatch, RealJukebox, and Windows Media Player. The selection of a player is mostly one of personal preference; the feature sets are fairly close.

The music is played through your sound card. The quality of your speakers will determine how good the sound is.

The cost of this software ranges from free to about $30. There is more expensive software, but the more expensive stuff does not look like it is worth the money.

The portable MP3 players are small solid state devices with no moving parts. They resemble Walkman-style FM radios (and sometimes include a FM tuner). Because there are no moving parts, you will never experience a skip from a jolt or dropping the unit. You listen to the music through a headphone; there are typically no speakers.

The current models have between 32MB and 64MB of memory to hold your music. This translates to about an hour of music. The more expensive units include removable memory, so that you can carry more than an hour of music with you.

The music is normally downloaded to the player from your computer via your serial port. Some newer models use the USB port for faster transfer. Some units require you to download to a memory card and do not connect the player itself to your computer.

These devices are great for joggers or people who listen to a limited selection of music. Lots of manufacturers are making these devices and people seem to be buying them. New unknown companies made the first devices but they are now being offered from name brands like Sony.

In addition to adding more memory, some manufacturers (like Sony) are trying to make them even smaller. Some of these units are not much bigger than the batteries that power them.

Okay, an hour or two is not enough music, so we need another, larger storage medium. A few disk-based jukeboxes are starting to appear.

These use the small hard drives used in laptops. A jukebox that has a 4.6-GB hard drive promises over 80 hours of music. These drives can give you 12 GB of storage today and the number keeps growing, so some future version will probably will hold every song you like. (It will always be too small for me.) Unfortunately, they are asking $750 for the unit. How well the hard drive will hold up is unknown.

About six months ago, component MP3 CD players started to appear. These devices resemble component CD players because they are indeed CD players.

The difference is, in addition to playing normal CDs, they can play CD-R (and maybe even CD-RW) disks that you create containing MP3 music. This gives you 10 hours of music on a single CD. Note that the play list for most radio stations is probably less than 10 hours. A carefully selected playlist on your CD, played on random, could be as satisfying as a radio station and you do not have to listen to stupid commercials or DJs.

These devices do not connect to your PC. You need to create the CDs with your CD burner.

The ability to play MP3 disks is also showing up on DVD players. After all, they need to distinguish themselves from their competitors.

The cost of these devices started at about $400, but is now under $200.

The MP3 CD players resemble portable Walkman CD players. They can play normal CDs and CD-R disks that you create containing MP3 music. The devices I have seen also play CD-RW disks.

Oddly enough, you may run out of batteries before you run out of music. Most of the current units get 7 hours of battery life, and the disk can hold 10 hours.

These devices also do not connect to your PC. You need to create the CDs with your CD burner.

The initial devices on the market were from unknown brands. Name brand units are starting to appear. I expect a lot of choices by Christmas shopping time. These devices should sell well in spite of their relatively high cost (between $150-$200). Well, high for a CD player, but it is not bad when compared to the 64MB players that hold an hour of music.

Note that current players do not show the titles and artists. They only show the track number so you will need a list of songs to find something in particular.

The missing option is something for your car. Okay, you can use a car adapter and use the portable unit, but that is not a good solution. You need full dash control. Guess what? It is available, but it is really expensive. The first device is by Kenwood and sells for $750.

There should be more (and hopefully less expensive) options available by Christmas. There is no sign of multi-disk players yet, but they are sure to happen. Imagine 120 hours of music loaded in your car. Who needs radio anyway?

To get some MP3 music to play, just pick a search engine and search for MP3. This will take you a specific search engine for finding MP3 files. You have to deal with the morality of actually downloading the illegal files yourself.

We will use the MusicMatch software to explain the steps in creating MP3 files. There are plenty of other programs that will work but MusicMatch is the program that both of us (Ken and Milt) currently use (that could change next month).

That's it. The songs are sitting on your hard drive as MP3 files.

CDDB (Compact Disk Database) is a Disc Recognition Service^sm (DRS) with a database of CD text information, used for CD recognition purposes. So, when you put a music CD in you computer's CD-ROM drive, your CDDB-enabled player will access their servers to identify the CD and download this information. This information is not stored on the CD itself. The database is used to match up the information that is available from the CD to an entry in the database. It uses the number of tracks and the track sizes. It is rare for two CDs to have the same exact number of tracks, in the same size, in the same order. In those cases where it does, the user selects the correct one.

Other users have made up the database. These users have entered the artist, album name, track names, and other information. This means that most of the time, when you load a CD, the titles will be there. The downside is that the entries may be incorrect or misspelled.

Winamp is one of the most popular MP3 players and has been around a long time (by MP3 standards). Winamp was launched in January 1998 by Nullsoft and acquired by AOL in June 1999.

Winamp resembles a stereo console with tape player type buttons and some other simple controls, as well as a graphic response meter. Of course, your typical stereo does not tell you the artist name and the song title.

Double-clicking on the title bar will shrink the player to a small bar that you can set to be on top of other windows. That way you can have control when that phone call comes in and you want to pause the music.

You can select the equalizer to give you more control over the sound.

Winamp introduced the concept of skins, which let you change the look of the player. You can even download a toolkit that lets you build your own skin and then upload it for others to use. A recent check on the Winamp Web site showed over 18,000 skins available. The skins can make the player look quite different. Some of the skins are very good but others are just plain strange.

Winamp also includes the ability to add on other third-party features like visualizations. They refer to these as plug-ins.

There are even games available as add-ons. Most of the plug-ins are free, and the others are shareware of one style or another.

Winamp does not rip CDs or create MP3 files. There used to be a third-party add-on that gave recording capabilities, but it did not go to 128 kbps and it has disappeared.

Nullsoft Inc.

In true Microsoft form, Microsoft added the best features from the other MP3 players when they updated Media Player. It now has features like skins and visualizations and of course can play MP3 files.

In large mode, you can look at your music library. It lets you look at the data by album, by artist, by genre, or everything. You can sort by any column to help you find the songs you want and move them to a playlist.

In small mode, you see the visualization and the controls along with the artist name and song title. The playlist and additional controls slide out from the side.

Microsoft has included some strange skins in the default download. There are plenty more on the Web—not as many choices as WinAmp but there has not been enough time, I am sure Microsoft will catch up. The skin preview is nice—none of the others really let you see before you select the skin.

Windows Media Player can rip CDs but it can only record in Microsoft's own compression format, Windows Media Audio (WMA), which is very similar to MP3. It will yield similar file sizes with equivalent settings, and sounds the same.

Windows Media Player does not use CDDB but it does use an equivalent service. It seems to find song titles as well as CDDB.

Windows Media Player is free. The most recent version is on the Web. The versions included with Windows 2000 and Windows ME are out of date.

Note that Windows Media Player 7 should not be installed on computers running Windows 95 or Windows NT 4.0. I do not know why, but that is Microsoft's strong admonition.

Microsoft Corporation

The folks at MusicMatch managed to make deals with equipment manufacturers to bundle their software with the equipment. This apparently gave them enough money to develop a mediocre player into a great player.

Like the other programs, it resembles component stereo equipment, but it adds a window that can show the album cover and a play list window.

MusicMatch has the most versatile music library on the market. You can view your music library by album, artist, genre, mood, preference, tempo, and year. Of course you will have to define most of that yourself.

You can also enter lyrics, notes, and bios for every song. Add a bitmap of the album cover to complete the package. The lyrics and cover art are readily available on the Internet.

MusicMatch includes features like skins (they call them themes) and visualizations. If you do not like one of the hundreds of themes available, you can download the developer's kit to make your own.

The free version allows you to record up to 160 kbps samples. You can choose between VBR and CBR. You can also select between MP3 or WMA files.

Clicking the Songs Directory button lets you decide how the files are stored. It is highly recommended that you use the track number and track name to name files. This will make it easy to play an album all the way through in order.

As a bonus, MusicMatch can make either music CDs or MP3 CDs from your playlist. You do not need additional CD-burning software (but you do need a CD burner).

MusicMatch is free. A registration fee gets you more features, including faster encoding and label printing. There is also an OEM version that you may get with a portable player.

MusicMatch

The RealNetworks people originated a competing streaming audio format (RealAudio), but finally jumped on the MP3 bandwagon and now offer both formats. To compete against the other players, they developed RealJukebox.

If you have ever used RealPlayer, you would expect RealJukebox to look like the others but it does not. In full view mode, RealJukebox does not look like a stereo component, even though it has the required controls. It looks more like a normal Windows program. The library is okay, but it only lets you select by genre and artist/album (albums under each artist). They do access all of the ID3 data, so they could add additional categorization at some time in the future.

Like the others, there is a skin mode, and RealJukebox has plenty to choose from. Mixed in with the strange skins are some of the nicest, most usable skins you are likely to find in any of the packages.

Yellow Submarine skin is a little weird but what better way to listen to Beatles music. Wait a minute, can you play Arlo Guthrie on a Yellow Submarine? I guess you have to, there is no Red VW Microbus skin (yet).

In addition to skins, RealJukebox also has themes. These change how the full mode looks.

RealJukebox displays the song information in a very attractive format. There are several options here, and those are probably downloadable, like skins and themes.

RealJukebox can record as RealAudio, MP3, or WAV files. The free version limits you to 96 kbps.

There are some concerns over what RealJukebox and RealPlayer are sending back on the Internet. They both request connections to the Internet when starting, even if you are running offline. Blocking these with a firewall still permits you to use the player. None of the adware critics have complained about the RealAudio programs, but the jury is still out.

RealJukebox is free. Paying a registration fee gets you additional features. Most importantly, registration gets you 128 and 160 kbps recording capabilities.

RealNetworks, Inc.

For the real fanatic, CDs do not have enough sound quality. There is currently an attempt to create a market for a higher quality recording. This format uses a sampling rate of 192,000 samples per second using 24-bit samples, versus the 44,000 16-bit samples used for CDs. Instead of just two channels of stereo, this format can handle six channels for surround sound. There are not many recordings available in this format and it is too early to tell if this format will succeed. This format uses DVDs for the recording media and is called DVD-Audio.

Expect to see a new compression format to support this format. This format cannot be handled by MP3, but I expect to see a new format that can.

Another change taking place is double-density CD-Rs. These should be appearing very soon. As the name implies, you will get twice the storage in the same size.

This means that a future generation of MP3 CD players could contain 20 hours of music (and 240 hours of music could fit in that 12-CD car deck). Then again, if we could use MP3 DVD-RWs, we could have about 800 hours of music. (You have that many CDs—don't you?) The future sounds great.