FEEL THE NOISE: Dolby versus dts for DVD - Technology Information

Emedia Professional, July, 2000 by Michelle Manafy

Dolby counters that the data rate of a digital coding system does not in itself define its sound quality; the company asserts that the compression algorithm used to decide what is kept and what is thrown away is equally if not more important. Dolby Digital's algorithm (AC-3) is based on decades of Dolby Labs research into how sound is perceived--thus the term "perceptual sound".

Jeff Stabenau, president of prominent east coast post house, Crush Digital, agrees. He's done comparisons for clients and says, "While it is often anticipated that dts will sound better--primarily due to the assumption that the larger data stream will contain a more accurate sound image--the result is that people usually find the two formats comparable."

In the DVD market, Dolby clearly has the edge. Because Dolby is one of the most recognizable names in audio, an emergence as the standard for HDTV broadcast, and stares as one of the two mandatory audio formats for DVD-Video discs, it has a daunting lead in the race for surround sound superiority.

Digital Theater Systems' DelGrosso says, "At this point, it is safe to say that dts digital surround is installed in every major brand around the world. Two years ago, we were at 10,000 in the field, a year ago 300,000 units in the field, now we are at 2 million." Dolby, on the other hand, can boast that every DVD player sold is equipped with Dolby Digital, though that doesn't mean every DVD owner is playing back in 5.1.

However, with the likes of Spielberg and Universal in its corner, and movies from Buena Vista, New Line, Paramount, Sony, MGM/UA, and Warner Bros. being released in dts, Digital Theater Sound continues to hold its own.

Artisan Entertainment's director of DVD production, Michelle Friedman, says she thinks "dts is just about the best sounding thing out there," but still comes up against the space versus sound issue on a regular basis. She says, "In the past, from what my authoring houses tell me, dts' bit rate was much larger. Thus, if you choose dts you have to sacrifice everything else on the disc. As I understand it, Universal and DreamWorks put out dts-only versions because of that." In Friedman's experience, DVD buyers are checking the boxes for the extras--commentary tracks, deleted scenes, bloopers--and she has had to allocate the space to these elements. However, she is planning to include a dts soundtrack on an upcoming release of Terminator, both because she believes movies warrant the best sound available and because she thinks that consumers want to hear what dts will sound like. "They see the dts logo and want to be able to hear both and compare the two."

For years, dts has been battling Dolby on a playing field of its own. Because of tight bit budgets, studios have had to put out two separate versions of movies to have a dts version on the market. Recently, dts has made a move that will provide studios with the option of variable bitrate--not quite the range that Dolby offers--but full (1.54mbps) and half bitrate (753mbps) versions. As with The Bone Collector, this allows studios to offer both dts and Dolby Digital 5.1 on one disc. This way, users can simply flip through the audio options on the disc and select their preferred sound. Perhaps this isn't exactly what dts had aspired to, but it will deliver dts into the ears of more consumers and, theoretically, allow them to make at-home comparisons that will convince them that dts is better. One could speculate that later in the life cycle of surround sound and DVD itself, dts could again reassert the full bitrate version as the superior alternative.