They are out there now, and more are coming: DVD players, television sets, set-top boxes, and receivers that include virtual surround technologies. Found under brand names such as TruSurround from SRS Labs and N-2-2 from Spatializer, these technologies envelop even those who are space, wiring, or speaker challenged in sound appearing to come from the front, rear, and sides.
Speakers and amps and wires—oh my!
The idea of experiencing 5.1-channel surround sound in their homes thrills most people until they discover how expensive and complicated it is to set up and adjust the equipment. A system requires five speakers (Left, Center, Right, Surround Left, and Surround Right) and typically also includes a subwoofer (represented by .1). Each must be positioned properly, wired to the main amplifier or receiver, and balanced—daunting tasks for someone who just wants to watch a good movie.
For many people this is the beginning and the end of their surround sound experience. Face it—standard surround sound is cumbersome. Only a true "audiophile" will purchase extra speakers, wiring, and amplifiers and conduct setup tests or adjust the speakers for the best listening possible.
Dolby Laboratories Inc., San Francisco, developed what is now the most prevalent system for delivering 5.1 surround to the home, namely, Dolby Digital. But the company recognized that an alternative to complex multispeaker systems would be required if it wanted to expand the appeal and hence the market of the system, which uses a five-speaker plus subwoofer system to deliver surround sound. Virtual surround, which needs only two speakers to create a surround sound image, was the answer to both Dolby's and the consumer's problems. Virtual surround sound systems mimic actual surround sound by exploiting the way that the auditory system perceives the direction from which a sound is coming. They can create a very realistic surround sound field from only two speakers placed in front, to the left and right, of the listener, as found in standard stereo systems.
The key lies in a so-called virtualizer, developed by companies such as SRS Labs, Spatializer, and Qsound. It turns Dolby Digital's 5.1-channel output into the two virtual surround channels.
Evolution, not revolution
In the late 1920s and early 1930s, researchers, noting that people listened to sound through one speaker but had two ears, began developing what came to be known as stereo.
Around the early 1970s, some people like Ben Baur of CBS, and Peter Scheiber, an independent consultant in Bloomington, Ind., mused that stereo was great, but everything seemed to be coming from in front of and between the two speakers. So quad, as it was called, was born, which used four speakers: left and right speakers in front of the listener as in conventional stereo and left and right speakers behind the listener to create the sensation of being "surrounded by sound" [see figure]. Quad failed to catch on and quickly died.
While quad was being developed, Dolby Labs was becoming very successful with tape noise reduction systems. Its first systems were designed for professional reel-to-reel units, but then Henry Kloss, founder of Advent Corp., implemented a simplified version of the technology on a cassette deck, giving Dolby an entrée into the vast consumer market.