Know Your Plugs - Part II

by Bob Seidel

Last week we talked about the correct plugs and wires to use for the audio aspect of your home theater system. This week we will cover video.

Connection changes in audio did not suffer from much evolutionary change over the past few years. In the beginning there was stereo (red and white connectors) and then the jump was made directly to digital cables, either copper or fiber optic. And that is where the state of the art is today. Video, on the other hand, has gone through a number of evolutions. Cabling up your home theater system will be a challenge because you need to figure out where in the evolutionary scale your various pieces of equipment reside.

In the beginning there was the standard coaxial antenna cable, whether this came from a cable box or from an antenna. Both the audio and video were carried by radio waves on TV channels and were of course all analog. This is the worst type of connection from a quality standpoint.

When separate stereo audio connections became common, the equivalent video was the single yellow connector, called Composite Video. This was an analog signal but did not use radio waves and was significantly better than a TV cable connection. A variant of this was the S-Video connector (a round, multi-pin connector) which has a better type of analog signal and again a better quality picture. Composite Video only supported standard definition TV.

Before digital video, the best type of connection was the Component (note, not composite) Video cable, which used three separate connectors. You might want to think of these as separate Red, Blue, and Green analog components although in fact it is more complicated than that. Component Video was still analog, but had the best signal quality to date, and also supported High Definition.

Now we come to the evolution to digital video signals. Unfortunately the PC makers and TV makers could not get together on a standard. The PC makers settled on DVI (Digital Video Interface), which uses a rectangular white connector. DVI was championed by VESA (the Video Electronics Standards Association) that goes back to the PC VGA display days; the TV makers championed HDMI (High Definition Multimedia Interface). I have written columns previously on these connection types. The major difference is that HDMI carried full digital sound along with the video, whereas DVI does not.

So getting back to the subject for these columns, if an installer comes to your home to set up a High Definition cable or satellite box (or other equipment), insist on the proper and best connection type even if you have to pay extra for the cables. As discussed last week, for audio that would be either coaxial or fiber optic digital cable. For video, you should specify HDMI, and use Composite Video (3 cables) only as an alternative if you TV does not support HDMI.

While on that subject, make sure that the cables you get are long enough to slide the equipment out of your shelf or enclosure. You need to be able to get to the back of your equipment to change or check cables. If the back of the cabinet is closed (as most seem to be), then you need to have enough slack cable to pull the unit out to work on it. I have seen cables that were too short and when you pull the equipment out it pulls the connectors right out of their sockets. This is because the standard RCA-type connector is just a press fit and has no locking screws or turns. And the biggest problem then is remembering or knowing where to plug the cables back into! So don't fall into this trap and make sure the installer gives you the proper length cables.

(Bob Seidel is a local computer consultant in the Southport - Oak Island area. You can visit his Website at or e-mail questions or column ideas to him at For specific inquiries, please call Bob Seidel Consulting, LLC at 278-1007.)