Sensurround
Sensurround is an audio process developed in the 1970s by Universal Studios for the presentation of theatrical movies. According to Halliwell's Film Companion, the process involved "the augmentation of violent action on screen by intense waves of high decibel sound, enough, in some documented cases, to crack ribs." Originally developed as a showcase for the Universal production Earthquake, the process was used in three subsequent films, Rollercoaster, Midway, and in the theatrical version of Battlestar Galactica.
Sensurround involved the installation of up to 10 special very large Cerwin-Vega subwoofer speakers in black-painted wood cabinets, which were placed beneath the screen and in the corners of the theatre. The sound system was driven by a separate control box attached to a 1,600 watt audio amplifier. When triggered by a separate secondary pickup on the film's optical soundtrack, the system generated a sub-audible tone in the 60 cycle range at 120 decibels, the results of which could be "felt," but not "heard." The Sensurround speakers only played the Sensurround track, and did not play any of the film's soundtrack. In the case of Earthquake, Sensurround was activated during the quake scenes to augment the conventional soundtrack.
The much-hyped Sensurround made Earthquake a popular "event" film, but never caught on during the age of budding multiplex cinemas due to disturbances it caused at adjacent theatres. When Earthquake opened in November of 1974, The Godfather, Part II opened the same month, often playing in the next theatre auditorium. Theatre managers were inundated with complaints from audience members, literally shaken, by the bleeding of Sensurround into the theatre exhibiting Godfather II. This disruption was not worth the effort for most theatre owners, nor was the $500 per week Sensurround rental fee charged by Universal.
The excessively loud Sensurround also caused additional disruptions for theatres playing Earthquake, including structural damage in some cinemas. The most famous example is that of Mann's Chinese Theatre in Hollywood, where theatre management strung a safety net over the seating to catch errant pieces of plaster after a test screening revealed Sensurround had actually cracked the ceiling. In Germany, Sensurround movies were only allowed to be played in single standing cinemas. When Earthquake was screened in Chicago, the head of the Chicago Building and Safety Department demanded that the system be turned down or removed, due to his concern that it would cause structural damage to city theatres.
Trivia
In 1974, Waldon O. Watson, Richard J. Stumpf, Robert J. Leonard, and the Universal City Studios Sound Department received a special Scientific and Engineering Academy Award for "the development and engineering of the Sensurround System for motion picture presentation." Subsonic Sensurround went through several different versions as the technology evolved, including "Sensurround II" and "Sensurround III."
Contrary to popular belief, Sensurround cannot be "heard" (as a "rumble"), but it is rather "felt."
DVD prints of Earthquake from Universal Home Video, released after May 9, 2006, feature the Sensurround track (described as "Sensurround 3.1," which is an update to "Sensurround III"). It is doubtful the theatrical Sensurround experience could be duplicated in the home, unless the viewer has a sound system capable of enormous subwoofer output.
The British DVD release of Earthquake reads "4.1 Sensurround," although when tested on very powerful home cinema equipment, it doesn't use the subwoofer quite as much as present-day action movies.
Cultural references
The alternative pop/rock band They Might Be Giants have a song called "SenSurround" (also spelled "Sensurround") which appeared on the soundtrack to Mighty Morphin Power Rangers: The Movie and their EP S-E-X-X-Y. The song makes several references to the theatrical audio technique, specifically to the film Earthquake.
External links
- Excerpts from the Sensurround manual at in70mm.com: