OTHER TECH

Digital Audio RecordingFor component-based digital audio recording, you have three choices: recordable CD (CD-R or CD-RW), MiniDisc (MD), and hard-disk recorders. Each has its strengths and weaknesses.

Recordable CD comes in two varieties: CD-R, which is write-once, and CD-RW, which can be erased and rewritten (the RW is for "rewritable"). CD-Rs are compatible with essentially all standard CD players. They play reliably in DVD gear that has separate laser pickups for CD and DVD but not in most single-pickup DVD players. You can send a CD-R recording to almost anyone and be confident he can play it. You can even play CD-Rs in your computer. But once you've recorded a CD-R, that's the way it will be forever. Given how inexpensive blank discs have become, few people are bothered by that anymore.

CD-RWs can be erased and rewritten thousands of times. Erasure is an all-or-nothing proposition, however. You can't go back to a completed CD-RW and erase or record over just one track on the disc - unless it's the last track recorded, and then you can usually work back from there. Also, CD-RWs will play only in machines specifically designed for them - most CD players and some DVD players won't play them. Finally, CD-RW blank discs cost more than CD-R blanks. So although all current CD recorders support both CD-R and CD-RW, you'll probably use the former much more often than the latter.

One small "gotcha" to look out for with CD-R and CD-RW blanks is the difference between computer/pro discs and those labeled for music or audio use. Audio discs are slightly more expensive than computer discs because of a royalty paid to songwriters and record companies, and are the only discs that can be used for recording in stand-alone consumer decks. They will work fine in all other types of recorders as well, however, including pro decks and computer CD burners. But if you try to record onto a computer disc in a stand-alone consumer deck, the machine will reject it. (For the pros and cons of computer- and component-based CD recording, see "Burning Choices," page 91.)

MiniDisc excels in the areas where recordable CD is weakest: editing and re-recording. You can add, remove, and reorganize the tracks on an MD to your heart's content. The discs are also small compared with CDs and analog cassettes, which makes MD a great medium for portable players.

To fit CD-length recordings onto such small discs, a perceptual-coding system called ATRAC is used to achieve about a 5:1 data reduction relative to CD. In MD's early days, ATRAC was justly criticized for slightly degrading the reproduction of some sounds. But the system has since been refined to such a degree that only the most persnickety listener could find anything to complain about. Recent MD decks also feature a technology called MDLP, which lets you record more than 5 hours of music on a disc.

But MD has never achieved the popularity in this country that CD has, so not many people own MD players. Indeed, when you first start making your own MDs, probably the only compatible com ponent you'll own will be the one you're using for recording.

The latest approach to home audio recording is perhaps the first not to rely on removable media. Instead, these recorders are built around high-capacity hard drives originally developed for computers. A 30-gigabyte (GB) hard disk, for example, can hold more than 50 CDs worth of music in its original, uncompressed 16-bit/44.1-kHz format. Apply an audio data-reduction system, such as MP3, and the amount of music a drive can hold soars. Suddenly you can have a personal jukebox capable of storing thousands of songs and retrieving any of them almost instantly.

There's no defined, standard format for hard-disk audio recorders. Some have built-in CD or DVD players in addition to digital and analog audio inputs and outputs. Others have Ethernet ports and other features designed for integration in to home computer networks, where they function as music servers. So it's very important to carefully consider what's available and how each product's features and capabilities fit into how you want to use such a device.

Note the type and number of inputs and outputs. Check which au dio coding formats are supported and wheth er the software in the box can be upgraded to add new formats or improved versions of existing ones. Some hard-disk recorders support CD-quality .WAV files as well as compressed file formats, such as MP3; others support only compressed files. Which compression formats are sup ported also varies, as do the data rates you can select for them. You want to be sure you can get the level of sound quality you want. For instance, a data rate of 160 kilobits per second (kbps) or higher will give you CD-quality sound, but it'll also eat up a lot of disk space. A rate like 96 kbps will free up a lot more room but also yield noticeably inferior sound.

If the jukebox contains analog inputs - most do even if you can't set the recording level - you'll be able to copy LPs or cassettes to the hard drive. You can even record radio programs from your receiver that are many hours long.

Finally, give the user interface a test drive. It's no good having a thousand music recordings right there in front of you if you can't organize them or find the ones you want quickly and painlessly.