New signal on cables

Television addicts can’t resist the crystal-clear pictures that high definition, or HD, signals provide. What they could do without is the knot of wires needed for the latest and greatest gear.

The modern-day cables that make HD signals a reality clean up much of that potential mess.

The advent of the HDMI (high-definition multimedia interface) cable means just one thick thread of wires connects a person’s television set to his or her cable box.

Such a cable became necessary thanks to two major changes to the home-entertainment field. For starters, every other electronic gadget, from cell phones to televisions, has switched from analog to digital signals. That means data is streaming as a crush of ones and zeroes, much like the way a computer reads information.

Then the HD revolution hit, or at least struck a chord with gadget-minded buyers who understood the complexities inherent in the new televisions. HD programming demands more bandwidth, or space to transmit data, than traditional sets.

Steve Koenig, senior manager of industry analysis with the Arlington-based Consumer Electronics Association, says HD technology initially required users to rely on a cable hookup called DVI, or digital video interface.

These cables packed all the video information into one beefy cable but required extra wires for audio signals.

“That’s why manufacturers went to HDMI. It’s a much more elegant solution,” Mr. Koenig says.

Leslie Chard, president of HDMI Licensing, says a key driver of HDMI technology is the need for precision on the home front.

Consumers shelling out big bucks for a new television don’t want the picture quality compromised in any way. Some cable formats will compress — and then decompress — digital signals to carry them more efficiently, but Mr. Chard says doing so threatens the loss of some signal quality in the process.

“When you spend this kind of money, you don’t want to be brought back to reality,” Mr. Chard says.

The HDMI format was created by seven companies — Sony, Panasonic, Hitachi, Toshiba, Philips, Thomson and Silicon Image — and thefirst HDMI cables came out at the end of 2002.

“It’s a constantly evolving technology,” Mr. Chard says, adding that each version is compatible with previous models.

The latest HDMI cable, version 1.3, hit the market in June.

“We doubled the bandwidth,” Mr. Chard says. That means the cables can transmit images sharper than today’s best sets can produce, but perhaps not better than tomorrow’s. The newest cable also lets a television display billions, not just millions, of subtle color variations. That will yield less on-screen “banding” — when a viewer can see a line where one shade of a color bumps into another.

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