If you've shopped for gear for a home theater, you've probably noticed that upconversion is a standard feature in lots of different types of equipment, including DVD players, Blu-ray players, LCD TVs, plasma TVs and even many home-theater receivers. For those unfamiliar with it, upconversion (also called upscaling) is the process used to transform standard-definition TV images to high-definition resolutions. One of our readers, Robert, recently wrote in to ask: "In a home theater, what component is best for performing upconversion, and is there any benefit in doing upconversion more than once?

To answer Robert's second question first, upconversion is only done once in the signal chain -- either at the source component (DVD player, Blu-ray Disc player, high-def cable box, etc.); the hub (home-theater receiver) if present; or the display (HDTV).Once upconversion is done, any other component that sees that signal will pass it along without further processing. 

As for Robert's second question, there's no hard and fast rule as to which component is "best" for performing upconversion. What is important, however, is that upconversion is done in the component that's the strongest performer in that regard since once the picture has been converted to HD resolution, that's the image quality that you'll see. That said, here are some things to consider: 

All HDTVs, including LCD TVs and plasma TVs, upconvert, and most do a good enough job of things to please all but the fussiest viewers. Some high-end TVs do even better in that regard. In our reports, we try to point out which HDTVs do an especially good job of upconverting, and which ones struggle a bit more. 

Budget home theater receivers often don't upconvert at all -- just pass on what they take in. Many moderately priced and high-end home-theater receivers do upconvert, and some do a decent to outstanding job of it. However, the most important task of a home-theater receiver is to produce outstanding audio, so audio quality should be the most important consideration when making a choice among competing models. 

Experts have long said that paying extra for an upconverting DVD player makes little sense for the majority of users. That's because most HDTVs generally perform nearly as well in upscaling standard definition to HD resolutions -- and sometimes they are notably better. That's especially true when it comes to today's low-cost upconverting DVD players. Still, there are some high-end upconverting DVD players and even some Blu-ray Disc players that do a pristine job of upscaling DVDs. If you demand the very best picture quality from your DVDs, those players deserve serious consideration.

If you already have a home theater but aren't sure which component does the best upconversion, don't be afraid to experiment. For example, set your DVD player to output a standard definition signal and see if your picture looks better or worse if you let your HDTV do the work of converting that to high-def resolution.