Disc quality is key to CD-Rs

Tips: Successful CD burning can be difficult, but starting with a quality disc is an important first step.

May 21, 2001|By Kevin Washington | Kevin Washington,SUN STAFF

CD burners have made it possible to combine the best of Bach and Destiny's Child on the same compact disc - prompting grand scale consumption of CD-recorder drives by computer owners new and old.

But using a CD burner at home can be as frustrating as sitting in traffic - you may wind up wasting a lot of time and get nowhere.

For example, you know you're in trouble when the first three CD-Rs out of a package of 50 discs are ejected from your $300 CD burner because it doesn't recognize them as being recordable. And prayer may be your only recourse when you discover that the CD-R you burned a week ago with five years of tax records can't be read by your computer, or anyone else's.

In either case, you may have fallen victim to poorly manufactured discs. While the odds of getting a bad CD are relatively small, industry experts agree that quality varies widely, and sadly, there are few tell-tale warnings of impending doom.

"Out of 100 discs, there may be as much as a 30 percent failure rate on some brands," says Chris Bailey, digital and optical products manager for disc and drive-maker TDK. "Some brands are pure marketers. With the smaller manufacturers, the quality may not be there, but they're selling cheaply."

If you do get a bad disc, you'll get little in the way of explanation from your computer. "The media just won't work at all - it won't be recognized, or you'll get to the end of the disc, have burned most of the information, and the disc will just kick out," Bailey explained. "It's a defective disc, and you wasted all of your time."

According to industry insiders, manufacturers rarely throw away blank CD-Rs that don't meet the highest quality standards. They often end up on a retailer's shelf or in the bargain bins at computer shows, where they sell for as little as 40 cents each in bulk.

"One day, you might buy brand X and it's pretty good. Then you buy something made by a different manufacturer and it's just awful," says Mike Johnson, general manager of Iomega Optical Business.

The good news is that you can avoid most headaches by careful shopping. The first rule, according to CD engineers, is to buy the discs that the drive manufacturer recommends. Check the instruction manual or the maker's Web site.

"If your drive manufacturer makes a disc," Johnson says, "you should buy that. Those discs have been tested by that manufacturer with that drive."

Second, look for a statement of accountability on the package. It can be a "lifetime" warranty, a technical support number or even a notice that the CD-Rs inside conform to so-called "Orange Book" specifications, originally developed by Sony and Phillips to provide industrywide standards.

Third, test the discs with your CD burner before you record anything that's critical to your existence - whether it's music or financial records. Then test the discs in your car's CD-player or your computer to see if they work.

Some recorders don't work well with some discs. "They're just bad combinations for a number of reasons," said Andreas Bohren, a physicist who works at Vivastar, a Swiss CD-R maker that has recently begun to offer discs in America.

A CD-R drive may not have enough laser power to burn the information deeply enough into a particular CD so that the disc can be used in every CD player.

"It's not so much just the media as the media and the writer," said Rich D'Ambrise, manager for engineering and new product development at CD-R maker Maxell.

To understand how CDs could be bad, it helps to understand a little about how they work. A CD-R consists of several layers - a clear polycarbonate substrate (the plastic disc itself), a microscopic layer of organic dye, a reflective metal coating - gold or silver - and a protective layer of some sort, usually a lacquer.

Blank CD-Rs can be written to only once. Newer, rewritable CDs (called CD-RWs) use different dyes made with inorganic materials so that the dye layer can be reformed as information is erased and rewritten.

When you record a CD, your drive shoots a laser beam through the clear substrate and into the dye layer, where it records digital ones and zeros in a pattern of tiny depressions, known as "pits," and unmarked areas called "lands." A CD player or CD-ROM drive reads the disc by bouncing a laser off the dye and reflective layers and analyzing the reflective pattern made by the pits and lands.

CD-Rs also differ from pre-recorded audio discs and mass-produced software CDs in one important aspect - the commercial CDs are "stamped" in bulk by precision machinery, while your CD-RW drive creates them one pit and land at a time.

Contrary to popular superstition, the color of the CD is not a sign of quality - it's created by the type of dye used and the color of the reflective backing. What's more important is the quality of manufacturing.

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