Difference Between Audio and Component Video Cables

by David Lipscomb Google

    Despite the prevalence of High Definition Multimedia Interface, or HDMI, cables, there is still a need for quality component video and analog audio interconnects. Although found with decreasing frequency on modern components, component video is capable of delivering high-definition video. Analog audio jacks are found on nearly every home theater device. Although analog audio and component video cables appear similar on the outside, they serve two very different functions.

    Component Video Overview

    Component video is identified by the trademark red, blue and green color coding. The cable jacket itself may colored or identified by a colored band around the connector's shell. Each cable within the trio must be 75 Ohms, necessary to prevent hindrance of the signal as it leaves the video device and travels to the home theater receiver or television. For this reason, it is possible to use three equal, separate lengths of RG-6 coaxial cables for longer component video runs. Component video remains the most commonly found alternative to HDMI with consumer video devices.

    The Composite Correlation

    To understand component video, it is important to address composite. The composite video circuitry places brightness, color saturation and video timing signals all on one cable. When used independently, composite video is capable of low resolution and is often filled with video noise. The three interconnects used in component video configurations are essentially three composite cables, although assigned different tasks by the component video circuitry. One cable carries the timing signals along with the green color primary and brightness cues. The other two cables carry the blue color intensity signals. You can therefore use three equal composite video cables as a component video cable. Separating these luminance and chrominance tasks among three separate cables vastly increases resolution and color accuracy, allowing component video to be used in high definition video applications that a single composite video system cannot handle.

    Analog Audio Basics

    Analog audio, or stereo patch, cables come in a wide variety of colors, RCA connectors and jacket appearance. Analog audio remains the preference for many audiophiles running dedicated stereo systems, and is necessary for hooking up subwoofers and external amplification. The wide price ranges often encountered with analog audio cables largely revolve around cable construction, the environment in which it is sold and measured performance. Since analog cables can be "tuned" by the manufacturer to elicit a certain type of sound through differing construction methods, care and experimentation is required to find the right sound for your ears with select audio components.

    Component Video Capabilities and Limitations

    Part of the reason HDMI was so quickly adopted by media executives and hardware producers alike is the presence of High Definition Content Protection, or HDCP. Encoded on certain software and enabled at the HDMI board inside each component, HDCP allows high-resolution video that remains encrypted against illegal duplication. Component video may carry the same resolutions as HDMI in most cases, but being itself an analog connection cannot be forced to carry this protection. For this reason many hardware producers prevent the highest resolution capability of select devices from being sent over component video. For example, if a device is capable of 1080p resolution over HDMI, this might be limited to 1080i or 480p over component. Unlike HDMI, component video cannot carry audio along the same cabling, necessitating a pair of analog cables or a digital cable such as optical or coaxial. It is for these reasons primarily that component video should be selected as an alternative to HDMI only if necessary.

    Analog Audio Considerations

    Analog cables enable stunning two-channel stereo audio performance. The only drawback to using analog audio is that the interconnect cannot carry digital surround formats, such as Dolby Digital and DTS. However, for stereo music and sources that are not surround-encoded, the choice remains perfectly acceptable. Additionally, analog cables over long runs may pick up noise and interference, causing a hum or other undesirable effects. Analog audio outside of a dedicated two-channel stereo system should therefore be considered only if optical, coaxial or HDMI digital alternatives are not available on the device.

    About the Author

    David Lipscomb is a professional writer and public relations practitioner. Lipscomb brings more than a decade of experience in the consumer electronics and advertising industries. Lipscomb holds a degree in public relations from Webster University.

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