Editing IMAX (section)

=== Soundtrack &ndash; double-system ===

To use more of the image area, IMAX film does not include an embedded soundtrack. Instead, the IMAX system specifies a separate six-channel {{convert|35|mm|in|abbr=on|sp=us}} magnetic film, recorded and played back on a [[Sound follower|film follower]] locked to picture, just as [[Vitaphone]] had been (utilizing 16-inch 33 1/3 RPM [[Old-time radio#Electrical transcription discs|electrical transcription discs]]) in the early 20th century, and was the same technology used to provide the 7-channel soundtrack accompanying films photographed and exhibited in the [[Cinerama]] process in the mid-1950s. By the early 1990s, a separate [[DTS (sound system)|DTS]]-based 6-track digital sound system was used, similarly locked to the projector by a [[SMPTE time code]] synchronization apparatus, the audio played off a series of proprietarily encoded [[CD-ROM]] discs. In the late 1990s, IMAX upgraded this system to use a [[hard disk drive|hard drive]] that carries a single uncompressed [[Audio file format|audio]] file. These are converted directly to analogue rather than processed through a decoding method such as [[DTS (sound system)|DTS]].  IMAX film and IMAX digital cinemas utilise a 6-channel surround sound system - with Left, Centre, Right speakers behind the screen similar to conventional cinemas, plus an additional "top center" speaker to create the effect of height in the screen.<ref>{{cite web |date=June 1, 1999 |title=Big Enough for Everest: Inside IMAX Sound |url=http://www.creativeplanetnetwork.com/news/news-articles/big-enough-everest-inside-imax-sound/373444 |access-date=April 26, 2017 |publisher=DigitalContentProducer.com}}</ref> There are also 2 rear left and rear right surround sound speaker, arranged as clusters of speakers rather than a spaced array of speakers such as used in a Dolby surround sound system. IMAX with Laser adds another 6 channels of sound: 4 channels of overhead speakers plus 2 extra side surround speakers.<ref>{{Cite web |title=The IMAX Difference {{!}} IMAX Melbourne |url=https://imaxmelbourne.com.au/about_imax/the_imax_difference/ |access-date=2024-06-04 |website=imaxmelbourne.com.au}}</ref>