to discover for myself, people often would not believe they were working until you switched them off. After Jack had employed them on a few shows with tremendous success, his rivals began to investigate the "Jack Mann sound." It was not long before both Sound Associates and Masque Sound invested in bozak speakers. Sound Associates eventually owned around a hundred. The other lesson I had from Jack was that there is an art in positioning and aiming the loudspeakers. It seems incredible now, but with the inferior columns we were using in the U.K.-all mid with little top or bottom-the general idea was to screw them to the proscenium wall wherever there was a free space and let them fill the auditorium with as much sound as possible before feed-back occurred. What Jack showed me was how to use the very defined wide horizontal and narrow vertical dispersion of his two-way columns. As he said: "You have to spray the audience with sound. The trick is to get the audience wet without wetting the walls of the auditorium. And you have to spray the people with an equal amount of sound. It is no good if two thirds of the audience get more sound than the other third." There was no possibility of getting yourself out of trouble by rigging a few delay speakers in the dead spots because the first useable digital delay units were only just about coming onto the market. Neither did one have the luxury of "room equalization" with Real Time Analysers and Graphic Equalizers. Altec had introduced their "Acousta-voicing" system in 1968, but it took some while for the idea to catch on. Jack Shearing's comment was that Acousta-voicing was the first real tool that could analyze what the sound was actually doing in an auditorium. before that you had to have "golden ears." S U M M E R 2010 theatre design & technology 15