Know Your Plugs

by Bob Seidel

I often derive material for my columns from everyday experiences, and this is another one of those. I was at a friend's house the other day and took a peek at his big screen TV setup. What I found was less than optimal, and we of course discussed what he would need to get the system working to its best potential. But there is an issue here that you as a consumer should be aware of.

If you purchase an entirely new TV and sound system from the ground up you would expect the installer to set it up correctly and rightly so. But if you just get new cable or satellite service on existing equipment, the installer is probably less motivated than he should be to make sure the job is done right. This is what happened to my friend. In this particular case, the installer did not hook up the correct audio cables from the satellite box to the receiver and because of that my friend was not getting true 5.1 surround sound. What he was getting was two-channel stereo. The receiver unfortunately played these two channels through the rear speakers also, simulating surround sound but it was actually only stereo.

So let's talk about the types of audio cables used in a modern TV hookup.

Back in the old days, all audio was two-channel stereo and used two cables, one for the left channel and one for the right. The cable itself usually had red and white connectors, and usually the two wires were joined together except at the ends. This audio was analog, not digital, and of course just stereo.

But there are now many 5.1 surround sound sources. For the uninitiated, that means five separate channels of audio being played on five speakers (the "5"). The sixth channel (the ".1") was for a subwoofer or LFE (Low Frequency Enhancement). Although not popular, 6.1 existed for a while and now 7.1 is becoming more available. 7.1 has a left, center, and right speaker in the front, two side speakers, and a left and right in the rear. Both your DVD player and your cable or satellite box can generate digital surround sound.

If these multi-channel audio systems used analog signals, you would have to have six or eight separate wires going from the source to the receiver. Because that is not practical, all multi-channel audio is digital and all channels can actually be carried on one wire!

So if you have a two wire, red and white connector cable going from one of your sources to the receiver, you are just getting old stereo and not surround sound. To fix it, you need to put a digital cable in place. There are two types, and either one is acceptable. Coaxial digital cables are standard copper wiring, while optical digital cables used a fiber optic cable. To figure out which one to use you need to look at what your sources are capable of generating and what your receiver is capable of accepting. You can usually find that information in the diagrams of the back panel connections found in the User's Manual.

But you may find that mismatches. For example, your receiver may have one coaxial input and one optical input. If you have two sources (DVD player and cable box) you would have to see what outputs they have. If your DVD has an optical output and your cable box has a digital output you are all set. But if both only have coaxial outputs and your receiver only has one coaxial input you have a problem. At this point it might be time to upgrade the receiver as most modern units have multiple inputs.

Once you plug in the correct cable, you would also have to configure the receiver (and possibly the other boxes) to use these channels. But once done, you will enjoy the full surround sound that really enhances movies today. But if you see a red and white cable in use, you are not getting the full capability of your receiver and it's time to upgrade.

(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.)