Tommy (film) - Quintaphonic Sound

Quintaphonic Sound

The original release of Tommy used a sound system devised by sound engineer John Mosely called "Quintaphonic Sound". At the time that the film was in production various "Quadraphonic" (four speaker) sound systems were being marketed to the domestic HiFi market. Some of these were so-called "matrix" systems which combined the four original channels into two which could be recorded on, or transmitted by, existing 2-channel stereo systems such as LP records or FM radio. John Mosely used one of these systems (QS from Sansui) to record front left, front right, back left and back right channels on the left and right tracks of a 4-track magnetic striped print of the Cinemascope type. A discrete center channel was also recorded on the center track of the print. The fourth (surround) track on the striped print was left unused. In addition John Mosely used DBX noise reduction on the magnetic tracks.

Unlike the usual multiple small surround speakers used in cinemas, the Quintaphonic system specified just two rear speakers, but of the same type as those used at the front.

One problem that arose was that by the 1970s the 4-track magnetic sound system was largely moribund. Only a few theatres were equipped with the necessary magnetic playback heads etc. and of those that did in many cases it was not in working order. So in addition to installing the extra electronics and rear speakers John Mosely and his team had to repair and align the basic magnetic playback equipment. So each theatre that showed Tommy using the Quintaphonic system had to be specially prepared to take the film. In this respect there is a similarity between Tommy and Walt Disney's Fantasia for which a special sound system (Fantasound) had been devised and required each theatre that showed it in the original release to be specially prepared. Also, like Fantasound, Quintaphonic Sound was never used again.

Tommy was later released with mono, conventional 4-track magnetic and Dolby Stereo soundtracks.