Sensurround

thumb|Sensurround speaker diagram, with the extra speakers shown in white (Center, Surround Left and Surround Right) thumb|Sensurround logo (designed for the release of the film Earthquake). Sensurround is the brand name for a process created by MCA and developed by Cerwin-Vega in conjunction with Universal Studios to enhance the audio experience during film screenings, specifically for the 1974 film Earthquake. The process was intended for subsequent use and was adopted for four more films, Midway (1976), Rollercoaster (1977), the theatrical version of Saga of a Star World (1978), the Battlestar Galactica pilot, as well as the compilation film Mission Galactica: The Cylon Attack (1979). Sensurround worked by adding extended-range bass for sound effects. The low-frequency sounds were more felt than heard, providing a vivid complement to onscreen depictions of earth tremors, bomber formations, and amusement park rides. The overall trend toward "multiplex" cinema structures presented challenges that made Sensurround impractical as a permanent feature of cinema.

Sensurround helped bring wider recognition to established loudspeaker manufacturer Cerwin-Vega, and aided in establishing a strong reputation for new audio amplifier company BGW Systems. The increased awareness of extended low-frequency sound reproduction that Sensurround brought to film audiences was a factor in the increase in subwoofer sales and in the rise in the number of subwoofer designs in the late 1970s and 1980s.