Common video interconnects
Video signals can travel over many different types of cabling, but the majority of video components are equipped with at least one of the following four types of jacks (listed in order from lowest-quality signal transfer to highest):
* coaxial RF, also known as F-type
* composite video, also known as RCA
* S-video
* component video
Used for connecting antennas, cable boxes, VCRs, TVs and more, coaxial RF cable (not to be confused with coaxial digital audio cable, above) can carry video and stereo audio information simultaneously. Standard coaxial cable is stamped "RG-59"; higher-quality "RG-6" cable features lower signal loss and better shielding, both of which are essential for DBS satellite systems and longer cable runs.
Composite cables plug into the composite video jacks found on many kinds of A/V components, including DVD players, VCRs, receivers, and DBS satellite systems. These jacks are often marked in yellow, and grouped with corresponding red and white stereo audio jacks. Composite video cables use standard RCA-type connectors, and are designed for high-quality video signal transfer.
S-video cables feature round, 4-pin connectors, and transmit the chrominance (color) and luminance (brightness) portions of a video signal along different paths. As a result, they provide better color accuracy and detail than either RF or composite connections do.
Found on most DVD players and HDTV tuners, and on a growing number of TVs and A/V receivers, component video connections deliver better detail and color accuracy than you get with RF, composite, or S-video. They do this by splitting the video signal into three parts, with each part transmitted via its own cable. Unlike the other three types of connections, component video is capable of passing high-definition and progressive-scan video signals.
Because of their higher frequencies, video signals are more susceptible to degradation than audio signals are, particularly while traveling through a substandard conductor. And, as with audio, radio frequency and electromagnetic interference can taint the signal. This can cause lines, snow, and other artifacts to appear on your TV screen. A higher-quality cable with a copper conductor, 75-ohm impedance, and double shielding can effectively preserve the strength and accuracy of the original signal.
Digital video interconnects
The shift to digital video sources and displays has led to digital video connections. There are two main digital video options: DVI cables and HDMI cables.
DVI (Digital Visual Interface) and HDMI (High-Definition Multimedia Interface) cables are especially beneficial if you're using a "fixed-pixel" display (like a plasma, LCD, DLP, or LCoS TV). Since these cables permit the video signal to remain in digital form all the way to the screen, you avoid the slight picture degradation that can come with translating the signal from digital to analog, and back.
Both DVI and HDMI cables can carry standard-definition and high-definition digital video signals. HDMI is also capable of carrying 2 to 8 discrete channels of digital audio (depending on the capabilities of the source component).
Most HDTV tuners and HD-ready TVs, and, increasingly, many DVD players now come with either a DVI or HDMI terminal; a few high-end components have both. (Also, HDMI cables are backwards-compatible with most DVI connections, so you can use an HDMI-to-DVI adapter to connect a component with a DVI terminal to one with an HDMI terminal.)
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*www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/home/cables.html
