EXPO '70 in Osaka, Japan. The first permanent IMAX projection system was installed at Ontario Place's Cinesphere in Toronto in 1971. The IMAX digital sound system was developed by Sonics Associates of Birmingham, Alabama. This system with 3 discs and 6 channels began to replace the multitrack magnetic tape sound systems used in IMAX theaters since 1971. In 1993, Sonic introduced the IMAX 3D sound system with 10 channels for the Sony IMAX theater in New York.
Low bass is handled by a pair of subwoofers behind the giant screen.
These amps are fed from four audio CDs, computer-synchronized with one another and with the projectors. The headsets can receive four separate soundtracks, so a movie could be presented in different languages simultaneously if the theater provides enough channels. Lynn McCroskey is President and CEO of Sonics Associates, a subsidiary of Toronto's IMAX Corporation. Another difference is the use of point-source surround, as opposed to the multiple small surround speakers used in conventional theaters. Overall IMAX system power varies depending on the size of the room, but it is typically in the range of 12,500 watts.