Choosing the Right HDTV Cables
Your brand new HDTV has arrived! It’s sitting in your living room, waiting for you to hook it up and start enjoying the fabulous picture. But then you peer around at the back of the set, and are confronted with a bank of multi-colored connectors and sockets looking for HDTV cables. This clearly is not your father’s television, which just had a place to connect the antenna (or cable service) and maybe three jacks for a VCR.
Now you’re confronted with something that looks like the control panel of the Space Shuttle. What are all those jacks? Will you need dozens of cables? Most importantly, how will you get it hooked up in time to watch tonight’s game?
Fortunately, the choices make a lot of sense when you break them down into manageable pieces. Once you are able to identify the different types of connectors, and know what they do, then you’ll quickly have your new set up and running. Note that cables may not be included, so you’ll need to know what to buy.
Listen To the Sounds
A good starting point is to understand that some connectors carry the audio signals, and others carry the video signals. In general, you will find a set of audio connectors associated with each video connector (or set of connectors).
In most cases, the audio connectors will be a pair of RCA jacks. An RCA jack is a round socket with a metal collar. The space between the hole and collar is filled with plastic, and this plastic is usually colored. These jacks accept cables that end in RCA plugs, which have a metal pin in the center with a rounded tip. The pin is in the middle of a socket with a metal ring around the edge. The pin and the ring each connect to one conductor in the wire, and mate with the jack.
Most audio connectors are set up as left and right stereo channel pairs. Almost all HDTVs color code the audio RCA jacks; the right channel connector is red, and the left channel is white. I find it easy to remember because Right and Red both begin with “R”.
Some video connectors will be associated with a stereo mini plug jack instead of RCA sockets. That is the same size as the headphone jack as used on iPods and other portable audio devices, and is often used on personal computer sound cards. One reason for using a mini plug connection is that it takes up less space; since the stereo plug connects three wires — left, right, and a shared ground — you only need one connector to take the place of two RCA plug connections.
A mini plug jack looks the same as the headphone jack on an iPod.
The other type of sound connection that sometimes appears on the back of an HDTV is a digital sound connection. In most cases, it is used as an output to pass along digital sound data to a home theater sound system. That can use either a single RCA jack, or it can use a fiber-optic connector that uses light to transport the sound data. If you have a home theater sound system with 5.1 channel surround sound that supports a digital audio connection, then use the digital connection, as this should give you the best audio performance.
Use the optical connection for digital audio for the best sound performance.
Better Picture With HDTV Cables
The next step is to divide and conquer the different types of video connectors. They fall into two categories: analog and digital. Note that this has nothing to do with the question of analog or digital broadcasts and tuners; it describes how the video image data is being delivered to the television set.
You don’t need to understand this difference in great depth, but analog sends the images as waves while the digital connection turns the images into individual bits of information. The key to this difference is that digital signals are much more precise than analog. It is much like the difference between a DVD which is digital and a VHS video tape cassette which is analog. The DVD will have a cleaner and more accurate picture than the VHS tape.
To get the best image on your HDTV, you want to use a digital connection, if possible. The most common connector for digital signals is HDMI, which stands for “High-Definition Multimedia Interface.” The socket looks a bit like a USB connector found on many computers, but it’s smaller.
The HDMI connector can carry both sound and video signals.
One interesting feature of the HDMI connector is that it is designed to carry both the audio and video signals. Many devices do not implement the audio portion of the connection, however, so it’s not unusual to find audio connectors associated with an HDMI jack. In general, use the HDMI for both the audio and video if both devices support it; if not, use separate audio connectors for the sound.
One important tip about HDMI cables is that you don’t have to spend a lot of money on them. The store salesperson may try to talk you into spending $100 or more for a single HDMI cable, but don’t waste your money. The quality of the cable matters a lot less for digital connections than it does for analog signals. In general, a digital connection is “pass/fail”; either a cable will work perfectly, or you’ll get very visible defects in the image. As a result, first try the cheapest cable you can find; they are available for less than $10. In the unlikely event that it doesn’t work, you can try one of the expensive choices.
If you cannot use the HDMI (or the closely-related DVI) digital connection, then your only other choice to display a high-definition image is to use an analog component connection, which uses three RCA jacks for the video portion of the signal, colored red, green and blue. The diagram below shows the three component video connections on the right, and the two associated stereo audio connectors on the left.
An analog component can give you a high-definition image.
You actually can use any RCA cables you want to connect to these component video jacks. Higher quality cables can make a difference, especially if you are running distances of 15 feet or more. One advantage to using a component video cable is that the connectors will be color coded, making it easier to get the right ones plugged into the correct jacks.
Color coded component cables make it easy to get the connections right on the first try.
There is another type of analog component connector that you may encounter. Many HDTVs come with a 15-pin VGA-style connector that is used on computer displays. It carries red, green, and blue signals, and is also capable of handling high-resolution images. It is a handy way to connect your HDTV to a personal computer.
A standard computer VGA connection can carry high-definition images.
While these two types of component connections can carry high-definition images, you may not be able to get the best performance from them. For example, the copy protection features in some blue-laser DVD players — Blu-ray and HD DVD — may only transmit the highest quality signal over an HDMI connection, and may degrade the image to a lower resolution if you use a component connection. That is intended to prevent people from copying high-definition DVD content, but it has the result that you don’t get the full image quality unless you use HDMI.
There are two other types of video connectors left: composite and S-video. Both are analog connections, and neither is capable of carrying better than a standard definition signal. Composite uses a single RCA connector, which is usually colored yellow. The S-video connector is a round DIN plug (which gets its name from Deutsches Institut für Normung, a German standards body) with four connections.
Composite and S-video jacks typically share stereo audio connections.
On most HDTV panels, you’ll find the composite and S-video connectors share a pair of stereo audio connections. You can use either the composite or the S-video channel, but not both at the same time. The S-video will give you the better image quality of the two, but both are limited to standard definition; you won’t get high definition with these connections.
S-video will give a better image than a composite connection.
So when making a video connection on your HDTV, the digital HDMI should be your first choice, followed by a component connection. Only use S-video or composite connections with standard definition devices or as a last resort.
Thanks to Syntax-Brillian Corporation for the use of the connector and cable diagrams.