Dolby Sound at the Movies

How Dolby and THX Work Together

To clarify a popular misconception, THX® is not a competing sound system to Dolby^® sound; rather, it is a set of parameters for cinemas created by THX. Dolby and THX coexist in high-quality cinemas all over the world to bring you a sound experience that is exceptionally close to what the filmmaker intended.

There are two subsets of equipment that comprise the sound system in a cinema. Dolby manufactures equipment for the "A" chain, which reads the soundtrack from the film, decodes it, and processes it. THX sets audio standards primarily for the "B" chain, the cinema's amplification and loudspeaker system that receives the signal from the "A" chain. THX standards also cover loudspeaker placement and acoustics.

To obtain THX certification, a cinema must comply with the standards and also use equipment from THX-approved manufacturers. All Dolby cinema processors are THX-approved, and by far the majority of THX theatres are Dolby installations. THX-certified auditoriums optimize the benefits of Dolby encoded soundtracks.

What does this mean for you as a moviegoer? That if you see both the Dolby and THX logos on the theatre marquee or in the newspaper, it's not a mistake: Dolby and THX can and often do go together. Choose a cinema that offers both Dolby Digital and THX, since the added dynamic range and frequency response a Dolby Digital soundtrack provides benefits greatly from playback in an auditorium that meets THX specifications.

The Dolby and THX combination can also be implemented in your home theater system. Home THX components optimize the reproduction of DVD soundtracks encoded with Dolby surround sound technologies.