So Long, CDs

For examples of MP3 audio files, See the sidebar ("MP3 vs. RealAudio")

Everyone's talking about MP3. Not since Larry, Curly, and Moe have three characters caused such a fuss. Depending on whom you ask, it's a format for compressing and storing sound, a way to download free music from the Internet, a promotional vehicle for musicians, a piracy threat to the recording industry, or a preview of how everyone will buy and sell music in the future.

In fact, MP3 is probably all these things. But most important, MP3 is the hot spot in the Internet music scene. Thousands of MP3 files in every musical style, many offering near CD-quality audio, are available for downloading (some even legally). What do you need to join the band? Just a free player and an Internet connection–the faster, the better, because MP3 files routinely weigh in at 5MB or more.

It's also easy to make your own MP3s. Run your favorite audio CDs through MP3 encoding software, and you can create nearly identical copies that use a fraction of the disk space. Stash a few hours' worth of MP3s on a PowerBook hard drive, and you've got a great alternative to the in-flight movie. Buy a CD burner and software such as Adaptec's Toast, and you can burn a CD-ROM that contains roughly ten hours of music, instead of the 74 minutes an audio CD can manage.

And you wonder why recording-industry executives have trouble sleeping.

Now the bad news: some of the most interesting destinations in the MP3 world have "Windows Only" signs on their doors. But the Mac is steadily gaining ground, and these days it's possible for the rest of us to participate in almost every aspect of the MP3 revolution.


Making Music Smaller

MP3 isn't new. Its origins go back to the eighties, when researchers began exploring ways to compress digital audio into less storage space. One of the standards that came from these efforts was MPEG (Moving Picture Experts Group) Audio Layer III–MP3 for short.

Uncompressed CD-quality stereo sound requires roughly 10MB of disk space per minute. MP3 can lower audio's appetite for storage by a factor of ten or more, and even audiophiles may have trouble hearing the difference. Like many audio compression schemes, MP3 relies heavily on perceptual coding techniques, which eliminate those portions of an audio signal our ears don't hear well anyway. It's similar to how the JPEG format works, compressing images by throwing away image data our eyes don't detect easily.

Variable Quality

Just because a file's name ends with MP3 doesn't mean you're getting CD-quality sound. As with all audio (and video) compression schemes, the quality of an MP3 file depends on how it's been compressed.

MP3 measures compression settings in terms of a file's bit rate–the average number of bits required for one second of sound. To obtain near CD-quality audio, MP3 requires a bit rate in the range of 128 to 192 kilobits per second.

Most high-quality MP3s on the Internet are encoded at 128 Kbps. As you can hear in our online examples, this yields near CD-quality sound. A 64-Kbps rate yields sound roughly equivalent to an inexpensive FM radio. At lower bit rates, you start to hear that swirly, shortwave-quality audio most commonly associated with RealNetworks' RealAudio and other streaming technologies.

Forget Streaming

It's obvious that a 128-Kbps sound file can't download over a 28.8-Kbps modem and play at the same time. In this regard, MP3 doesn't compete with streaming-media systems such as RealAudio and RealVideo. You can listen to a RealAudio feed within seconds of clicking on a link, but if you're downloading a high-quality MP3 file via a modem, you may wait half an hour before hearing the first note. This is why some MP3 music sites also provide RealAudio clips that let you preview tunes before committing to long downloads.

MP3 does allow a crude form of real-time streaming–but with quality compromises similar to RealAudio's. In other words, if you compress an MP3 file for very low bit rates, it has that shortwave-radio fidelity common to streaming audio.

This illustrates a key point: Although MP3's compression skills are impressive, MP3 itself isn't the holy grail of audio compression schemes. The reason MP3 files sound so much better than, say, live RealAudio feeds is largely because MP3 audio isn't compressed to the same degree.

But as anyone who's followed Microsoft Windows knows, a technology doesn't have to be the best in order to become the most popular. What does make MP3 magic are the free or nearly free tools for playing and making MP3 files–and the staggering number of MP3 files available for easy downloading.

Steal This Song

So is MP3 legal? The answer depends on where you get your MP3 files. If you've downloaded a free MP3 file from an official Web site or a clearinghouse like MP3.com ( http://www.mp3.com ), bought MP3 files from MP3-for-sale sites like GoodNoise ( http://www.goodnoise.com ), or created your own MP3 files from your personal collection of audio CDs, you're in good shape as long as you keep those files to yourself. It's even legal to convert MP3s with a utility such as Rafael Lubbert's free MPecker Drop Decoder and burn them onto standard audio CDs, so long as they're for your personal use.

But if you're downloading albums by commercial recording artists in MP3 format, chances are pretty good that you're engaging in music piracy.


Pontis Electronic' MPlayer3 is a forthcoming Mac-compatible MP3 player.

Auditioning MP3 Players

Macworld Lab tested five Mac MP3 players: @soft's MacAmp 1.0 (a shareware product still in beta testing at press time); Norman Franke's free SoundApp 2.6; Oliver Dreer's free beta version of MPEG Audio Player 1.7; the free beta of MacPlay3 1.4, from Germany's Fraunhofer Institute, where MP3 originated; and Audioactive's free Audioactive 1.2a, a relabeled version of MacPlay3. All five are currently free for downloading, so you can try them and find out which one you like best.

Snazzy Features

All of the players we tested provide playlist features that enable you to specify the playback order of a virtually unlimited number of songs (see the sidebar "Digital DJs"). And all except MacPlay3 and Audioactive enable you to save and switch between playlists, change the playback order by dragging song files up and down within the window, randomize playback order, and repeat tracks.

Interface Champs

Then there's the look-and-feel. MacAmp is the hands-down coolest MP3 player for the Mac, sporting a style that wouldn't seem out of place in a bachelor pad's stereo cabinet. Better still, you can customize MacAmp by downloading skins –small documents that transform the program's appearance. You'll find dozens of skins at @soft's Web site, which thoughtfully includes previews that let you see what each one looks like. MacAmp also supports plug-ins that add unique display features; the version we tested included a plug-in that creates a hypnotic graph of a file's frequency spectrum.

MacAmp is also the only player with a graphic equalizer, with sliders enabling you to boost or attenuate certain frequencies. And PK Industries' $5 shareware StripAmp 1.0 gives you easy control over MacAmp from within the Control Strip.

MacAmp also has a junior sibling: the $5 shareware MacAmp Lite 1.5.1, which provides a simple, Control Strip-like interface and can play numerous audio formats in addition to MP3 files.

Finally, Oliver Dreer's MPEG Audio Player has a unique feature for varying a song's playback speed in real time. Besides letting you make the Beastie Boys sound like Alvin and the Chipmunks, this feature could be useful for musicians who want to play along with a tune or slow down a song to decipher a complex solo.


Ripping Your Own: MP3 Encoders

To make your own MP3 files, you'll need an encoder application. Some MP3 buffs also call these rippers, and refer to encoding a track from an audio CD as ripping.

We tested two encoders: Rafael Lubbert's free MPecker Encoder 1.0 (still in beta at press time) and Xing Technology's $30 AudioCatalyst 1.01. Both work well, but if you're serious about MP3, spring for AudioCatalyst.

Each program makes encoding audio CD tracks easy (see the screen shot "Speaking Encode"). You can encode one track at a time, or rip an entire CD in one fell swoop. MPecker also supports Layer II encoding, while AudioCatalyst supports a variable-bit-rate encoding scheme that can yield better sound quality but may cause playback glitches with some players (see the sidebar "MP3 Tip Sheet").

Disc Master

The MP3 specification supports a tagging scheme for storing song, artist, and album information along with the encoded file. When an MP3 file contains these tags, this information appears in the MP3 player as the file plays.

Both MPecker and AudioCatalyst can add these tags, but AudioCatalyst goes the extra mile. It can connect directly to the Compact Disc Database (CDDB) at http://www.cddb.com, an Internet-based service that contains information on tens of thousands of CDs. Load a series of tracks into AudioCatalyst, choose the Fetch Track Information command, and the program connects to CDDB and adds the information for each track. On the downside, AudioCatalyst can't read track information you may have entered already using Apple's AppleCD Audio Player utility or normalize track volumes, although Xing Technology says those features will be a part of its forthcoming AudioCatalyst 2.0.

When Macworld Lab put the two utilities through their paces, AudioCatalyst came out more than twice as fast as MPecker in compressing a 4-minute Audio CD track (see the benchmark, "MP3 in a Flash"). Indeed, AudioCatalyst is fast enough to permit real-time encoding. Connect an audio source such as a tape deck or turntable to your Mac, and you can make MP3s from your favorite cassettes or vinyl albums. (Note that a turntable's output isn't strong enough to drive the Mac's audio-input circuitry; you'll need to connect a preamplifier between the turntable and the Mac.)

It's also worth noting that BIAS's (800/775-2427, http://www.bias-inc.com ) $499 Peak 2.0 and $99 Peak LE 2.0 audio editors can also encode MP3s. There's no reason to buy either program if you simply want to encode audio CD tracks, but they would be useful if you want to edit audio before encoding it.


Fade Out

So what aspects of the MP3 craze can't Macs participate in? For starters, there's MP3 player hardware such as Diamond Multimedia's $200 Rio (800/468-5846, http://www.rioport.com ). This tiny gadget (3.5 by 2.5 by 0.625 inches; 2.4 ounces) connects to the parallel port on a Windows computer and holds about an hour's worth of MP3 music. It's impressive enough to have attracted the attention of lawyers from the Recording Industry Association of America (RIAA)–last fall, the RIAA unsuccessfully sued to stop shipment of the Rio.

Diamond Multimedia says it's looking very hard at the Mac market, and it wouldn't come as a shock to see a USB version of Rio someday. In the meantime, if you're in a multiplatform office or school, you can use a Mac for downloading and encoding, and then turn to a Windows machine to load MP3s into a Rio.

Meanwhile, Germany-based Pontis Electronics is putting the finishing touches on its MPlayer3 ( http://www.mplayer3.com ), a Rio-like device that will work with Windows and Macs alike. The $159 MPlayer3 should be available by the time you read this. Numerous other companies are working on similar devices, including ones that fit in a car's dashboard (see http://www.mp3.com/hardware/ ).

Streaming Servers

Windows also has the edge in MP3 streaming. Nullsoft, the maker of WinAmp, the Windows world's most popular MP3 player, has developed an MP3 streaming system called Shoutcast ( http://www.shoutcast.com ). The Windows- or Unix-based Shoutcast server, which you need for streaming your MP3s to the world, is free for noncommercial purposes; commercial users pay $299. A related, Windows-only program called MP3Spy (from the company of the same name at http://www.mp3spy.com ) lets you locate Shoutcast stations and chat in real time with other listeners.

Shoutcast is fun, but RealNetworks' RealAudio streams more reliably, has good Mac support, and is far more popular for live streaming. By the time you read this, RealNetworks' free RealPlayer will also support MP3 streaming.


The Last Word

MP3 is a grassroots groundswell–its popularity comes from millions of enthusiasts embracing an open standard. But Big Business has taken notice. Several companies (including Microsoft) are now promoting MP3 enhancements or alternatives they say provide better quality, piracy protection, the ability to purchase songs you download, or all three.

MP3's ubiquity has made it a de facto standard for high-quality compressed digital audio. On the Mac, the tools of choice are @soft's MacAmp for playback and Xing's AudioCatalyst for encoding. But given that nearly all MP3 tools are free, there's no reason not to try the other programs reviewed here, too. Use them honestly–to play legally distributed MP3s and to make MP3s of your own CD tracks–and you'll discover new artists and get more out of your own music library.

A contributor to Macworld since 1984, Contributing Editor JIM HEID ( http://www.heidsite.com ) specializes in Web and digital-media technologies.

July 1999 page: 88

Digital DJs

MacAmp's default skin

The relatively staid-looking
MPEG Audio Player


MacAmp's highly stylized skin

@soft's MacAmp is the premier MP3 player for the Mac. By applying downloadable "skins," you can transform the program's look-and-feel. Or use the more basic interface MPEG Audio Player offers.

MP3 Tip Sheet

Make 'Em Sing

You can't launch an MP3 player by double-clicking on a freshly downloaded MP3 file, because the MP3 file lacks the internal type and creator codes that tell the Mac which program to launch.

To open a downloaded MP3 file, drag it to your MP3 player's icon. With most players, you can also drag and drop an MP3 file into the playlist window.

With a disk utility such as Daniel Azuma's $10 FileTyper (available through shareware sites), you can add the appropriate type and creator codes to downloaded MP3s. To have the Mac launch MacAmp when you double-click on an MP3, change the MP3's type to MPEG and its creator to mAmp (note the capitalization).

Ripping Smart

When encoding stereo tracks for high-quality playback, start with a data rate of 128 Kbps and the Joint Stereo mode. (Joint Stereo is an encoding scheme that improves the quality of low and midrange frequencies.) For encoding monophonic tracks, you can use a 64-Kbps bit rate. Lower data rates are also ideal if disk space is tight or if you're encoding voice-only material.

Burn Your Own

To commit your MP3s to a CD (for your own use), you need a CD-ROM burner and software. The premier burning software for the Mac is Adaptec's $99 Toast (408/945-8600, http://www.adaptec.com ). If you burn an ISO 9660-format CD, PCs and Macs alike can read it.

If you want to burn an audio CD, you need to convert your MP3s into AIFF format. You can do so with the free SoundApp utility.

MP3 vs. RealAudio

WHEN IT COMES TO PUTTING MUSIC ON THE WEB, BANDWIDTH --NOT FORMAT-- STILL MAKES ALL THE DIFFERENCE

If you ever intend to add music downloads or any other type of RealAudio or MP3 elements to your Web site, you need to know the difference in sound quality of the varying formats and download rates. For comparison purposes, we've compiled several different versions of the same music sample at numerous connection speeds compressed for two different technologies: MP3 and RealNetworks' RealAudio.

To check out the differences in quality of these music samples, just click on the links below. You will need RealNetworks' RealAudio Player and an MP3 audio player such as MacAmp Lite to listen to these samples.

128.mp3 (1.1MB)
64.mp3 (620K)
32.mp3 (316K)

isdn.ra (768K)
56.ra (308K)
28stereo.ra (192K)
28mono.ra (156K)

The first thing you'll notice is the obvious: the higher the bit-rate, the better the sound quality.

Other things to note: · At modem-speed bitrates, MP3 acquires many of the undesirable aural artifacts commonly associated with RealAudio. And similarly, at higher bitrates, RealAudio clips compare favorably with MP3.

The RealAudio clips use bandwidth much more conservatively than does MP3. The "ISDN-quality" RealAudio clip actually demands only 80kbps -- far short of ISDN's 128Kbps maximum throughput. Similarly, the 56K modem clip uses just 32kbps, and the 28.8 stereo clip uses just 20kbps. RealAudio provides this extra slack to accommodate for network delays and disruptions.

About the Music The sample, "My Old School," was written, performed, and recorded by Geoffrey Cook, a musician located in Pacifica, CA. The song is from his CD, "Big Sound." For more information, see http://home.att.net/~geoffrey_cook/Music.htm.

Other Online Music Technologies Numerous companies are building on MP3 or offering their own technologies that provide high-quality audio downloads but with greater copyright protection and more electronic commerce potential than MP3 provides. Here are two notable examples.

Liquid Audio, http://www.liquidaudio.com. A veteran of the music e-commerce scene, startup Liquid Audio earlier this year announced that it was jumping on the MP3 bandwagon and building MP3 support into its Liquid Music System. a2b Music, http://www.a2bmusic.com. Hip name, hip site -- would you expect anything else from, uh, AT&T? This AT&T spin-off's technology promises 11:1 compression ratios (file sizes roughly similar to MP3's), with support for downloading album artwork and purchasing.

For additional information on Web audio files, check out the feature in the July 1999 issue of Macworld magazine, as well as John Fu's online column, MP3: The Bare Facts.

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