by Paul Sanders
High-definition televisions, Blu-ray disc players and other HD devices require better connector cable technology to transmit HD sound and picture data between devices. High-definition multimedia interface cables, usually called HDMI cables, have quickly become the most popular choice for HD devices. Here are the answers to some frequently asked questions about HDMI cables to help you cut through the jargon and understand how HDMI will affect how you experience music, movies and games.
What are HDMI cables used for?
HDMI cables are used to transmit HD sound and picture information between home theater devices like HDTVs, Blu-ray disc players, video game consoles and home theater receivers. This is a big improvement over other types of connector cables that don't transmit HD data or transmit only video or sound. Also, HDMI cables can transmit back and forth, allowing your HDTV to send information back and forth to your other HD devices. This allows for more complex features to be built into things like Blu-ray discs.
How does cable length affect HDMI?
When an electrical signal is transmitted over a wire cable, it meets resistance, which can degrade the signal; the longer the cable, the more conductive material a signal has to pass through. A thicker cable has lower resistance, which is measured in "ohms." Most HDMI cables will work great if they are shorter than six feet. As long as you're not running an HDMI cable longer than 50 feet, you probably won't see a loss in video or sound quality. A lower resolution picture can travel farther without losing integrity; but with high resolutions, like 1080p, it's best to limit the length of your HDMI cable.
Will my HDMI cables be usable in the future?
Currently, HDMI cables use about half of the signal bandwidth they are capable of, which leaves a lot of room for improvement. New connector cable technologies will take advantage of this extra HDMI cable bandwidth, but even the most state-of-the-art devices now available work well using HDMI.
What's the difference between HDMI 1.0 and HDMI 1.3?
Since HDMI technology first appeared, specifications have changed. All later HDMI specifications are backwards-compatible with previous specifications, meaning a HDMI 1.3 cable includes all the capabilities of a HDMI 1.0 cable. The later versions of HDMI cables have higher speed, color, connector and other abilities. These improvements have been made for HDMI cables to prepare for future improvements and capabilities of HD devices.
What type of video does HDMI support?
HDMI cables support 720p, 1081i and 1080p video formats. If you have an HDTV that uses "enhanced definition" formats like 480p, HDMI cables will support that as well. HDMI cables can also carry SD formats.