Q What is the purpose of the optical digital audio out port on my TV? Can that be used instead of my HDMI port for sound from my receiver? Is HDMI as good or better than optical digital?

BRIAN JOHNSON, Motley, Minn. A The optical digital audio connection is used in conjunction with the TV's digital tuner. Many HDTV owners use an antenna with their HDTV to watch local HD channels. When you tune a channel with the TV's digital tuner, a signal will be sent to the optical output. By connecting the TV's optical output to a surround receiver, you can enjoy your programming in surround sound just as if it were from a DVD. (Not all programming is broadcast in surround, so sometimes you will only hear the front speakers.)

HDMI stands for High-Definition Multimedia Interface and for most applications it is considered superior to an optical connection. Unlike the optical connection, which carries only digital audio signals, HDMI carries both audio and video signals. HDMI transfers uncompressed digital signals for better audio/video quality and incorporates elements of DRM (Digital Rights Management) to prevent copying. This was done at the behest of movie studios and other content providers.

Besides the potential for better video and sound quality, a big advantage to HDMI is that you need only one connection between components. If you have an HD DVD or Blu-ray player, an HDMI receiver that supports Dolby TrueHD and DTS-HD decoding is a must. The best entry-level option is the Onkyo TX-SR605, which retails for under $499.

As more and more audio/video receivers incorporate video processors, HDMI becomes increasingly important because it can send the cleanest possible video signal to the receiver. If you connect a DVD player to a receiver/video processor via HDMI, you can use the receiver not only to select what you want to watch, but to change picture settings by component without changing the TV input.

The ultimate for home theater buffs is a receiver or surround sound processor featuring top-quality video processing and all the components connected via HDMI. If your component uses a top-quality video processor you can make your DVDs and cable/satellite broadcasts look their best and tweak the picture from each component to perfection. If you want a taste of high-end video processing with your HDMI receiver or surround sound, look for models using Gennum VXP or Silicon Optix HQV video processing.

Speaking of HDMI connections, there's no need to spend $150 on an HDMI cable. You can get a premium-quality HDMI cable from monoprice.com for under $5, a savings of $146 per cable. If you are connecting a cable box, a DVD player and a receiver to a TV, that's four cables and a savings of almost $600. Use the savings to get a better receiver, a better TV or better speakers.

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