instead featuring three cars hanging behind the drum kit. All of the projection screens were replaced with video cubes, as the projectors were not bright enough for the European summer nights when daylight lasted later. The resulting video system used three Digiwalls of projection cubes, four Vidiwalls (each 4 cubes high by 3 cubes wide), and thirty-six Barco monitors. Comprising 178 cubes, the three Digiwalls varied in orientation: 14 cubes high by 6 cubes wide, 9 high by 5 wide, and 7 high by 7 wide. Williams said the new video system was "vastly superior" and that the changes made Zoo TV "the largest touring video facility ever created". The sound system utilised 144 Clair Brothers' S4 Series II cabinets positioned in "two curved wings". These speaker stacks were 38 feet behind the drum riser and 45 feet behind the primary vocal position. The layout allowed for sightlines of 250 degrees within stadiums. To help focus the sound, the engineers installed a semicircle of Clair Brothers' P4 cabinets, comprising four arrays of six cabinets each, around the perimeter of the stage. Additional P4 speakers were placed on their sides on the edge of the B-stage. Underneath Bono's position at the front of the main stage were 16 Servo Drive sub-bass units. The concert at Roundhay Park in Leeds was supplemented by time-delayed speaker towers from SSE Hire due to the venue's elongated shape, making it the only show on the tour to use delay speakers. For the "Zooropa" monitor speaker system, Radio Station in-ear monitors were provided by Garwood Communications. The monitors were mixed with four Ramsa WS-840 consoles, with Skaff serving as the monitor engineer for Mullen and Clayton, and Vish Wadi for Bono and the Edge. The European leg featured confetti cannons, provided by Shell Shock Firework Co. and JEM, that shot "Zoo Ecu" banknotes (which were substituted by "Zooropa" condoms in Ireland). Planning, itinerary, and ticketing Rehearsals for the tour began in December 1991 at The Factory in Dublin. The band found it challenging to recreate all the sounds from the new album. They considered using additional musicians, but their sentimental attachment to a four-piece prevailed. The tour was announced on 11 February 1992, less than three weeks before opening night. The opening leg consisted of 32 arena shows in 31 North American cities, from 29 February to 23 April. Four days after the tour announcement, tickets