The transition from a standard TV system to HD doesn’t stop with buying a new TV. New cables, stereo components, audio formats, and, of course the HD disc format war all come into play, according to Electronic House on Friday.

The first task is to understand HDMI. This cable format carries both the video and audio. But many customers will want to separate out the audio before it gets to the inexpensive speakers built in to most HDTVs. Selecting good quality cables without paying too much is important.

�Keep in mind that as great as digital is, there can still be problems�a skinny little wire can have signal issues,� says David Wiswell, group manager for product development and engineering at Panasonic Projector Systems Company.

The second issue to be aware of is the number of HDMI inputs on the HDTV. Some older HDTVs may have too few, and one doesn’t want to be constantly plugging and unplugging cables. Many companies now make HDMI switch boxes that accept many inputs and have one output to the TV. Some have remote controls. [Make sure the switch box can carry along the HDCP protocol.] More expensive switch boxes can actually switch automatically based on sensing which input is active.

In terms of HD quality, it’s not always true that HD from, say, a Blu-ray player is the same as HD content provided by cable and satellite sources. The screen resolution is the same 1080(i/p), but the compression systems vary and that can affect the image quality.

Mark Jackson, president of EchoStar Technologies (parent company of satellite provider Dish Network), has noted that "high-definition bandwidth limitations presented an initial challenge for all content providers, but MPEG-4 compression, new modulation methods, and advanced hardware helped overcome these restrictions."

The format war between Blu-ray and HD DVD has been extensively covered, but there are some new technologies coming along that can protect the customer’s investment. Samsung has announced a dual-format player that will be able to play both formats. And Warner studios is pushing a "Total HiDef Disc" (THD) that puts the Blu-ray version on one side of a disc and HD DVD version on the other.

Finally, there are many audio formats to consider. The thing to remember is that HDTV carries along with the video an AC-3 audio component that can drive many speakers. That signal needs to be preserved and brought into a next generation A/V stereo receiver with HDMI inputs so that it can decode the audio and send the sound to the customer’s speakers.

If that’s not possible, the customer can still use traditional optical or coaxial audio, but options are more limited.