Editing Subwoofer (section)

===Cinema sound===
After the introduction of Sensurround, [[movie theater]] owners began installing permanent subwoofer systems. [[Dolby Stereo#Dolby Stereo 70 mm Six Track|Dolby Stereo 70 mm Six Track]] was a six-channel film sound format introduced in 1976 that used two subwoofer channels for stereo reproduction of low frequencies. In 1981, [[Altec Lansing|Altec]] introduced a dedicated cinema subwoofer model tuned to around 20 Hz: the 8182. Starting in 1983, [[THX]] certification of the cinema sound experience quantified the parameters of good audio for watching films, including requirements for subwoofer performance levels and enough isolation from outside sounds so that noise did not interfere with the listening experience.<ref name=THXOverview /> This helped provide guidelines for multiplex cinema owners who wanted to isolate each individual cinema from its neighbors, even as louder subwoofers were making isolation more difficult. Specific cinema subwoofer models appeared from [[JBL (company)|JBL]], [[Electro-Voice]], [[Eastern Acoustic Works]], Kintek, [[Meyer Sound Laboratories]] and [[BGW Systems]] in the early 1990s. In 1992, [[Dolby Digital]]'s six-channel film sound format incorporated a single LFE channel, the "point one" in 5.1 surround sound systems.

Tom Horral, a Boston-based acoustician, blames complaints about modern movies being too loud on subwoofers. He says that before subwoofers made it possible to have loud, relatively undistorted bass, movie sound levels were limited by the distortion in less capable systems at low frequency and high levels.<ref name=Barron1998 />