Understanding audio in the DTV era

Many viewers have been upgrading their televisions to go digital. For those who are confused about 5.1 vs. 7.1 or CD quality vs. HD audio, you're not alone.

Mark Casavant is a speaker guy. He's with Klipsch, headquartered in Indianapolis. The facility is not only their corporate headquarters, but it's also a research center. To get the most of that research they need a very quiet room, one with no echoes called an anechoic chamber.

"So when we measure products in here, it is the pure output of the sound system," said Cesavant.

Many of those systems are surround sound.

"5.1 is fantastic for most home environments. If you want to go the extra route with the extra surrounds of 7.1, it enhances it," said Casavant.

5.1 means three front speakers and two surround speakers behind. The point one is a subwoofer. 7.1 includes two more side speakers. Casavant recommends spending a little more on the center-channel speaker up front.

If that's not enough, Blu-ray offers HD audio, this means that the audio is not compressed. In order to cram thousands of songs onto an iPod, for example, the digital audio files have to be compressed. So what's on your iPod is probably not CD quality, but HD audio is. However, there are settings in iTunes that will allow you to rip CDs at a higher quality.

Klipsch's new line of surround sound speakers runs around $500. On the high end, a pair could run around $20,000. And while that end may be out of your price range, when buying speakers, Casavant said you get what you pay for.

Casavant added that a very light speaker is probably weaker. When it comes to sound, look for something with a little more heft.