frequency bass speaker setup consisting of four huge speakers  loaned by distributors to select theatres showing the film. This  system was employed only during the quake sequences of the film, and  was so powerful that it actually cracked plaster at some movie  theaters. "Sensurround" was employed in only three other films  released by Universal: _Earthquake (1974)_ (qv),  _Midway (1976)_ (qv), and the theatrical release of  _Battlestar Galactica (1979)_ (qv).