You could spend $20 or less for a cable to connect your DVD player or cable box to your television--or you could spend hundreds. But how do those cables differ?
While conventional wisdom says a wire is a wire, a poorly constructed cable can seriously degrade video quality. Used with a digital connection, a bad cable can mangle pixel data, resulting in a speckled image; with an analog link, it can distort the signal, resulting in faded colors or blurred details. So the question is not whether a good cable is essential, but whether you need to spend a lot to get a good one.
To find the answer to that question, the PC World Test Center evaluated analog and digital video cables from five vendors: budget-cable companies CableWholesale.com and StarTech.com, industry leader Monster Cable, and boutique brands AudioQuest and Kimber Kable. For analog connections, we tested the three-wire component-video cable--the only common analog interconnect that can carry high-definition TV or progressive-scan DVD signals. For digital connections, we used High-Definition Multimedia Interface (HDMI), which carries digital video and audio signals (though we tested only the video portion).
Prices for the component cables ranged from $18 (CableWholesale.com) up to $275 (AudioQuest). The HDMI cable prices ranged from $31 (CableWholesale.com) to $300 (Monster Cable). And since cable length is an important factor in testing--each additional foot has the potential to worsen the signal--we chose cables that measured about 4 meters (12 to 15 feet) each, long enough for the majority of home theater setups.
Judging cable quality by eye is tricky. It's hard to know, for example, whether a problem stems from the cable, the TV, the signal source (such as a DVD player), or the content. But a signal analyzer can isolate the cable from the mix and measure its ability to transmit data. Video generators produce top-quality images for diagnosing problems such as incorrect colors or blurriness.
We began our evaluation by checking the cables on precision test equipment. Then we used generators to send pristine video signals through the cables so we could view the results on TVs. We tested at least two cables of each model examined. Some cables came to our test center direct from the vendors; others, we bought.
All cables are designed to transmit signals well, but certain tests can be used to determine how well an individual model performs. For the digital cables, we tested the three color components, the copy protection signal, and the device identification--all parts of the HDMI specification. In the case of analog cables, we measured impedance, return loss, and insertion loss.
Our conclusion: You don't need to spend a fortune on cables. The HDMI cables performed comparably in both our instrument tests and our visual tests. And with analog cables, the analyzer revealed some degree of variation in quality, but the variances did not translate into noticeable differences in our visual tests.