The release on laser disc of Clear and Present Danger and True Lies in early 1995 heralded the next step in home theater sound, Dolby Digital. These titles were the first to incorporate a new digital soundtrack with five discrete full-range channels–left, center, right, left surround and right surround–plus a sixth low-frequency effects channel. First introduced on motion picture film in theaters, Dolby Digital is now being featured on the new CD-sized DVD video discs, as well as laser discs, and as part of the new U.S. digital broadcast TV system.
Among the advantages of Dolby Digital are the added sonic reality and excitement made possible by its extra surround and low-frequency effects tracks. Dolby Digital and Dolby Surround will coexist and complement each other for years to come, however, so you needn't hesitate to invest in home theater equipment with just Pro Logic for now. Dolby Digital, for example, has much the same speaker and amplifier requirements as Pro Logic.
If you decide not to start out right away with Dolby Digital capability in your home theater system, prepare for adding Dolby Digital later by getting a Pro Logic unit designed specifically for upgrading with an add-on Dolby Digital decoder unit. Whatever your future plans, though, you can start building a library of Dolby Digital laser and DVD discs now and enjoy them for the time being in regular Dolby Surround.