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Being new to the home theater game, I am confused as to when one would use an RGBH/V cable vs. an RGB 5 channel Component high resolution cable. What is the difference between these items, and when would you use one over the other?


Also there seems to be a vast difference in pricing on RGB 5 Channel Component high resolution cables (from $135-$300 on 25 ft. runs). All the specs appear the same. Is there some qualitative difference between the expensive and inexpensive cables?


Thanks,

hermann
 

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Hi Hermann-


I think you might be trying to differentiate between an RGB cable and a component "breakout cable."


Here are some basics concerning video signals and cables/connectors:


RGB and component are two distinct types of video signals. The former sends each color (Red, Green, or Blue) as a discrete signal and derives the luminance for the video signal from them. Most often, separate sync signals (H and/or V) are sent separately as well in an RGB signal.


A component signal also keeps the color components separate from each other. It is broken down into a luminance signal (the Y), and two color difference signals (the Pr and Pb).


Now, the important thing to remember is that both of these signals can be carried on different types of cables using different types of connectors. For example RGB signals are commonly carried on VGA cables with 15-pin connectors. They can also be carried on coaxial cable with BNC type connectors (those bayonet-looking connectors you often see on CRT projectors). There are either 4 or 5 cables/connectors depending on the sync signals being transmitted.


Consumer component signals are most commonly carried on video cable with 3 RCA-type connectors at each end. However some video devices (like the NEC LT150 for example) also accept a component signal via VGA 15-pin connector. In other words, the only input on the projector is a 15-pin computer input. If you wanted to send a component signal from say a DVD player (with the standard 3 RCA-type connectors) to the NEC, you would need a cable that has a 15-pin connector on one end, and the three separate wires on the other to plug into your DVD player. That's where the component breakout cable comes in. These cables are usually a 15-pin VGA connector on one end and a 4 or 5 BNC connector on the other. What people most often do is buy inexpensive BNC to RCA adapters from Radio Shack and simply plug in only the Y, Pr and Pb cables to the back of the DVD player. You don't need to worry about the other sync cables because in a component signal the sync information is carried on the luminance (Y) waveform.


As far as the difference between component and RGB signals, it really boils down to what features your display and video components have or don't have. For example most projectors won't let you access certain adjustments (like color, aspect ratio etc.) when receiving an RGB signal. That's why LT150 owners desire the component signal via breakout cable referenced above.


Hope this helps,


Kirk
 

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Wow Kirk, really clear post. Thanks for taking the time to put that together.


Kelly
 
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