Now aside from watching DVD movies, DVD players can serve a few other functions. Obviously, for the PC, a DVD drive can function as a CD-ROM drive as well, adding to its overall value. But did you know that a set top player could play CDs also? They can even play Video CDs, which, while not big in the U.S. have caught on like wildfire in Asia.
There are some differences between the functionality of a DVD drive versus a set top player, however. For example, without a decoder card for your PC, you are incapable of getting the Dolby Digital six channel sound (also called DD5.1-5 for 5 speakers, and the .1 for the subwoofer). The PC drives are also not capable of generating a component video output (generally higher quality than even S-video) even with a decoder card. Finally, there are many more value-added features to be found on the set top players. These include features such as onboard decoders for DD5.1 (more on this later), multiple trays, and last but certainly not least, a remote control.
To anyone who has heard a DVD movie in full surround sound, there is absolutely no comparison to VHS, Broadcast TV, CD or otherwise. The choice of audio solution is one of the biggest decisions to be made while shopping around for a DVD player. The added cost for a Dolby Digital decoder is very expensive, but may be well worth it. Dolby Digital (or AC-3) is a compression algorithm that intelligently removes sounds that would not likely be heard, and intensifies the sounds that would be heard best by allowing them more sound resolution.
Most new DVD movies now have Dolby Digital 5.1 sound tracks which contain six discrete audio tracks, one for each speaker (2 fronts, 2 backs and a center) and then one for the subwoofer. Note: This is NOT Dolby Pro Logic, and there IS a world of difference between them. While Pro Logic takes a stereo (2 channel) source and interpolates rear and center channels, DD5.1 actually is encoded with six distinct channels.
A growing number of movies are beginning to support DTS (Digital Theater Sound) now as well. This format is similar to DD5.1 in that it makes use of six discrete channels, but DTS uses 20 bits to store it's audio data instead of 16. To some, DTS is a huge upgrade over DD5.1, but as most modern A/V receivers can handle both, you shouldn't have to choose between them. Whereas DD5.1 allows for multiple tracks in different languages and director's comments etc., DTS uses all of the available audio space to store a single soundtrack. While some may not like the lack of director's comments or multiple language tracks, audiophiles have taken a liking to DTS, and many CDs are now coming out with DTS support.
As most DVD buffs would tell you, aside from the improved picture quality, the audio is the reason they adore the DVD technology. Of course it all comes at a price. To be able to play a movie with the digital sound fully portrayed in six channels, of course you will first need the six speakers: two front speakers, two rear speakers, a center speaker, and a subwoofer. Although passable sets can be found for well under the $500, you will find many of the DVD buffs out there have invested in sets worth well over $1000. Before buying any speaker set, it is highly recommended that you listen to it yourself, and get a good feeling for what it is you want. Regardless, this is a hefty price to pay, and there is still more.