Stereo Of course, it all begins with stereo (a left channel and a right channel), which some consider to be the purest form of audio reproduction. We each have two ears, right? Stereo is the most accurate translation of any perceived sound for the simple reason that it’s the closest to human physiology. Even today, most audio components ship with a cheap pair of RCA-style audio cables for stereo connections—even though the components are generally capable of so much more.
CDs, VHS tapes, and even most DVDs are encoded with stereo tracks, and we’ve been happy with stereo sound for years. It’s natural. It sounds good. But to get the most out of today’s multichannel enticements, you’ll really need to get past the notion of the superiority of stereo. Multichannel technology doesn’t necessarily pretend to offer realism in movie soundtracks or music—it wants to wow you. It wants to reach into your pleasure center and open up new realms of sound appreciation.
Dolby Surround Dolby Laboratories has always been a surround-sound pioneer. The company’s first surround effort was Dolby Surround, a three-channel technology that sent discrete sound information to the left and right speakers, as with a stereo setup, but added a mono rear channel whose information was split into two speakers at the back of the room. The mono surround tracks were limited in their frequency, so the experience typically amounted to mere ambience, but it was the first real step toward the surround sound we know today.
Dolby Pro Logic II and IIx You probably have quite a few DVDs labeled Dolby Surround, but in truth, they’re four-channel Dolby Pro Logic discs. The next step above Dolby Surround, the Dolby Pro Logic technology sends discrete information to the front left, front right, center rear—and a new center channel. An essential innovation in the evolution of home-theater sound, the center channel takes care of a lot of sound at the center of the screen, and not just dialog.
The innovation of Dolby Pro Logic is that the four channels occupy only two audio tracks. Dolby decoders use a technique called matrixing to pull four channels of information from essentially a stereo signal. Of course, this is a perfect design for components (e.g., most VCRs) that are capable of outputting only two audio channels. Magically, Dolby Pro Logic conceals the channels inside that stereo track, indicating which sounds should come from the left, right, center, and rear speakers. You’ll find that many VHS tapes and even some DVDs are encoded with Dolby Pro Logic on their stereo tracks to create an immersive surround experience.
Dolby’s recently unveiled Dolby Pro Logic IIx format extends the functionality of Dolby Pro Logic II by expanding all two-channel and 5.1-channel information for playback in 6.1 and 7.1 environments. The result is an even more seamless, wraparound sound field that doesn't require specially encoded program content.
Dolby Digital Dolby Digital (aka AC-3) is the market's surround-sound standard for films, providing heavenly multichannel sound for movie theaters and DVDs. Dolby Digital significantly upgrades Dolby Pro Logic by offering six discrete channels of sound for use in not only DVDs but also games, HDTV broadcasts, and high-end music CDs. The more capable your system, and the more speakers you have surrounding you, the more profound your experience of multichannel bliss will be.
Dolby Digital 5.1 Six-channel Dolby Digital surround sound is designated 5.1—five full-frequency channels and one for the subwoofer’s low-frequency effects (LFE). The specific wonder of Dolby Digital 5.1 is that it sends discrete signals to the left-rear and right-rear channels. The availability of independent sound channels in the rear—essentially an entirely new stereo track intended solely for surround effects—transforms films into a truly enveloping aural experience.
Dolby Digital 5.1, combined with the soaring popularity of the DVD, has changed the way we enjoy entertainment. The two technologies, taken together, deliver far higher sound quality than we’ve ever known in the home. A case could be made that it's because of this loving marriage of technologies that surround sound has blasted off for so many forms of entertainment. Take gaming, for example: Gone are the days of lifeless (mono) Nintendo. You can now enjoy true surround-sound first-person shooters, in which you are the character, in the game, with danger coming from all directions. And if it weren't for the popularity of Dolby Digital 5.1, we wouldn't be enjoying the benefits of today's increasingly fascinating audio innovations.
Dolby Digital EX As much as you might have despised Jar Jar Binks and perhaps the rest of Star Wars: Episode One: The Phantom Menace, the debut of that film introduced the next stage in the evolution of Dolby Digital. Dolby Digital EX improves on Dolby Digital 5.1 by adding a center-back channel between the existing left and right rear channels—essentially, directly behind your head. This channel is a matrixed channel that derives its information from the existing left-rear and right-rear channels. If you have the right setup—and you will need a capable Dolby Digital receiver to realize the full potential of EX, as well as EX-encoded discs, which are still relatively rare—you will melt liquidly into your sofa or easy chair in a puddle of audio ecstasy as those rear-channel effects swirl around you.
so, call me dumb, but whats better - dolby digital or DTS? I've got a sony 5.1/dts amp and use the digital input, however when I play a movie in dolby digital 5.1 and then change the option to DTS and play it, I cannot tell the difference - is DTS better than Dolby?
audio-newb -March 4, 2004
I'm with the author. I've got a pretty good system, high-end Onkyo with a Polk setup, and I can rarely tell the difference between DTS and Dolby. DTS usually sounds louder at the same level, but that doesn't mean anything. Occasionally, DTS sounds a little more open, and tighter in the bass, but the differences are never (or at least rarely) astonishing.
DVD Dude -March 5, 2004
Nice try. But you stated the very problem that keeps many of us from investing in a home theater setup. There are too many versions of the software! And how many channels will be necessary? Do I really want to clutter my living/TV/listening/entertaining space with all those speakers and wires? Here's what you need. Two speakers. GOOD ones. They'll throw a nice wide soundstage so you won't even need a center channel. If you want dinosaurs romping through your room, get a sub. End of story!
ihatems -March 9, 2004
To ihatems, I think the article is talking about equating movie theater sound in the home. For that, you need a multichannel setup. Most of us understand the beauty of a good stereo setup and the soundstage it can create, but for movies, it's gotta be 5.1 or more. Otherwise, you're missing out on a lot. I agree that there are too many options. But I've never had a case where a DVD has been unplayable because of my lack of hardware. If you don't want to go above Dolby 5.1, you don't have to.
raider -March 10, 2004
To 'ihatems', if you do not want to clutter your living space then don't but I would recommend re-reading the article before giving advice cause it sounds like (from your post) that you missed something along the way. There is nothing better than wrap-around sound when watching a movie at home. I wouldn't mind seeing a 10.1 but you would have to ask how much is too much. At what point are you get not seeing any improvement in sound quality. Either way we are nowhere near that point now so bring on the technology. BTW...MS>L
Wolf -March 10, 2004
To ihatems --
I wouldn't worry about what's coming in the future. Get what's hot right now and enjoy it. I love my 5.1 surround sound, and a movie anywhere else just plain sucks. Do I need 6.1 or 7.1? Definitely not? Is it cool? Sure, but I'm happy with what I have.
Get yourself a 5.1 surround system for a few hundred bucks and see what you've been missing. You can always upgrade later.
Jim -March 10, 2004
Hi All I tend to agree with "ihatems". A pair of quality front speakers make me satisfied`. I also understand that if you want to take full advantage of movie sound, you need multich. systems, but they are rather expensive when demanding a certain quality level.I use Audiovector M3 Signature stereo speakers, really good sound experience for music AND film - thats it`!
Carsten -March 11, 2004
Fun article. Timely, too. Just bought back center speakers for DTS 6.1 ES. There's not many dvds out there that have 6.1 ES, but it's amazing.
Grady -March 11, 2004
DTS vs Dolby Digital. To me personally DTS wins hands down. More oomph to the soundtrack especially concerts. I currently run a 6.1 system and the sound is nothing short of breathtaking. I look forward to more channels to totally envelope you in the film the way the director truly wants us to be.
Robert -October 17, 2004
Who knows about some movie in 7.1?
Roosevelt -April 7, 2005
This article was very informative. There was something that was not really covered. What if you just installed a 7.1 setup? I have left, center, right...then surround left & right...then surround back lef & right. Finally, a sub woofer. I cannot get my Denon 3805 to display "Dolby Digital". It only sets it to Dolby Pro Logic IIx. Am I better off disconnecting the surrounds, and going with Dolby Digital with 5.1, or staying with Dolby Pro Logic IIx with 7.1???
Any suggestions & explanations would be most appreciative.
The innovation of Dolby Pro Logic is that the four channels occupy only two audio tracks. Dolby decoders use a technique called matrixing to pull four channels of information from essentially a stereo signal. Of course, this is a perfect design for components (e.g., most VCRs) that are capable of outputting only two audio channels. Magically, Dolby Pro Logic conceals the channels inside that stereo track, indicating which sounds should come from the left, right, center, and rear speakers. You’ll find that many VHS tapes and even some DVDs are encoded with Dolby Pro Logic on their stereo tracks to create an immersive surround experience. 
Dolby’s recently unveiled Dolby Pro Logic IIx format extends the functionality of Dolby Pro Logic II by expanding all two-channel and 5.1-channel information for playback in 6.1 and 7.1 environments. The result is an even more seamless, wraparound sound field that doesn't require specially encoded program content. 
Dolby Digital (aka AC-3) is the market's surround-sound standard for films, providing heavenly multichannel sound for movie theaters and DVDs. Dolby Digital significantly upgrades Dolby Pro Logic by offering six discrete channels of sound for use in not only DVDs but also games, HDTV broadcasts, and high-end music CDs. The more capable your system, and the more speakers you have surrounding you, the more profound your experience of multichannel bliss will be. 
As much as you might have despised Jar Jar Binks and perhaps the rest of Star Wars: Episode One: The Phantom Menace, the debut of that film introduced the next stage in the evolution of Dolby Digital. Dolby Digital EX improves on Dolby Digital 5.1 by adding a center-back channel between the existing left and right rear channels—essentially, directly behind your head. This channel is a matrixed channel that derives its information from the existing left-rear and right-rear channels. If you have the right setup—and you will need a capable Dolby Digital receiver to realize the full potential of EX, as well as EX-encoded discs, which are still relatively rare—you will melt liquidly into your sofa or easy chair in a puddle of audio ecstasy as those rear-channel effects swirl around you. 
Email this Article
Printer-Friendly
