Liberty, Justice, and High Def For All

The conversation subject of high definition is no longer segregated to the dark smokey rooms of the cultural elite, the same rooms where gas price conspiracies, global domination rituals, and secret handshakes are created. No friends, high definition is now available to bond and free, to all races and creeds, to rich and, well, semi-rich.

Pick Your Poison

HDMI and DVI are the two digital interfaces that are quickly becoming the prefered vessels of High Definition. Just as a quick recap...

DVI: Short for Digital Video Interface, came into fruition to convert analog signals into video signals to accomodate both analog and digital monitors. DVI-A is an analog signal, DVI-D is a digital signal, and DVI-I is an integrated analog and digital solution. This quickly became a popular interface because the integrity of the signal remains true through any transmission, unlike its analog grandfather, who loses little bits of data here and there because of too many treks through the snow as a kid.

HDMI: Short for High-Definition Multimedia Interface, this digital interface is perfectly suited for the consumer electronics market. It supports uncompressed high definition video plus multi-channel audio in a single cable, simplifying the install process for you and me. It does all this with a smaller connector than its DVI cousin.

Length Limits

Both DVI and HDMI signals begin to degrade in quality when sent over copper wire after about 5 meters. Although sometimes a well-made copper HDMI or DVI cable can send the signal further than that without corruptions visible by the naked eye, you will often encounter specks and glitter in the display, plus a host of other possible problems if the voltage level isn't preserved and stable.

Below is some basic information about what is available for DVI Extension and HDMI extension.

Extension

So, you've sold the farm to buy your HDTV display and source boxes, but the picture has more specks and sparkles than tinkerbell. If its because of long runs of DVI or HDMI cables, there are solutions. Gefen, a leader in the industry, manufacturers perhaps the most respected and prolific digital extenders for both home and professional A/V.

There are two basic ways to extend HDMI and DVI. Extend over a CAT5 cable, or just get a booster (similar in many ways to a repeater).

Cat5 Extension

This style of digital video extension uses two little boxes: a receiver and a sender. By "little", I mean a few inches by a few inches, by a few more inches. The sender sits near your source (such as a computer, a set-top box, a DVD player). An included cable connects your DVI or HDMI source to the sender. The sender sits near your video source and sends the signal long distances over a tidy and economic Cat5 cable. The receiver sits near the display and receives the signal that has travelled over long distances unscathed from video corruption. The receiver feeds the perfect image (with the resolution also preserved) to your display via your DVI or HDMI cable. The Cat5 Extension option is very attractive because Cat5 cables are very inexpensive and are neater than the fat (no matter how phat) video cables. I highly recommend Gefen products for their industrial strength, aesthetic attraction, and reliability in important video extension projects.

Boosters and Repeaters

Although not entirely identical, boosters and repeaters accomplish the same job and in a similar manner. Boosters and repeaters only require one box to sit at the end of a long run of DVI or HDMI cable. The unit simply corrects any signal corruption that has occurred over long runs of copper cable. This option is most appealing to those who already bought a long run of DVI or HDMI cable. Boosters and repeaters are also good for chaining multiple runs of cable together.

Cameron Postelwait works in business development at Sewell Direct.