In a large-scale event that demonstrates the ability of JBL VERTEC® line arrays to provide even coverage and high output in the most acoustically challenging outdoor venues, rental sound company LP Unlimited Productions provided the sound reinforcement system for a major regional religious event, “Loftus For Jesus,” held at Loftus Stadium in Pretoria, South Africa. The event featured some of the world's most prominent Christian leaders and drew a crowd of more than 70,000 people—the largest crowd ever assembled in the outdoor sporting facility.
The sound reinforcement system was required to cover the entire outdoor venue, using temporary staging and ground-support structures. Having been awarded the contract for sound reinforcement services at the upcoming major event, LP Unlimited Productions worked together with JBL's distributor for South Africa, Wild+Marr, to plan for rental-system expansion with new JBL VERTEC line array system components. The technical production team evaluated the stadium architecture and advance audience-area plans, relying upon JBL's Line Array Calculator software tool for system configuration decisions. It was decided to employ a total of 28 VT4889-1 full-size line array elements, 32 VT4888 mid-size line array elements and 34 VT4880 full-size arrayable subwoofers to implement the event system design.
For the event, which served as the inaugural outing for LP Unlimited's new full-size VERTEC system elements, the setup included two main left/right arrays, each made of 14 VT4889-1's. Out-fill arrays each included seven VT4888 loudspeakers and eight VT4880 arrayable subwoofers. An 18-box center ground-stacked subwoofer array was set up for ultra low-frequency support, using 18 VT4880 subs. This center VLF cluster was configured as a steered array, with a 120-degree, figure-8 polar response coverage pattern for the main audience area on the field. Side subwoofer arrays of VT4880's augmented low frequency coverage on the far side seating areas at both pavilion ends, as well as areas behind the stage.
In addition, three signal-delay towers, each comprising six VT4888 mid-size line array elements, were in use at the rear of the massive stadium. All JBL speakers were powered by Crown I-Tech amplifiers, and four dbx 4800 DriveRack loudspeaker management systems were in use with one unit dedicated as a multi-zone matrix and audio distribution device. Harman HiQnetâ„¢ System Architect Software provided remote control and monitoring of the signal processing and amplification.
"This was our first large-scale deployment of the new VERTEC system, and the loudspeaker system had to be very intelligible over extreme distances," observed Colin Loock, Technical Director for LP Unlimited. "Going into the event, we at first thought it would be a challenge to provide live-music sound reinforcement for so many people with only 60 high/mid boxes, for an official audience tally that ended up being 71,280 persons on show day. We needn't have worried. During setup, JBL's new V4 DSP presets made it very easy for us. And we immediately discovered that our new VT4889-1's have a very detailed high/mid section that complements its rich, present low end with the two 15-inch drivers. We were also very surprised about the strong low frequency performance that we achieved with the VT4880 subwoofers in an outdoor stadium application, with headroom to spare. As things turned out, we had quite a lot of headroom left on the VT4889-1's as well, even running at concert levels when the band performed. The VERTEC rig performed exceedingly well and beyond our expectations."
LP Unlimited Productions can be reached at www.lpunlimited.co.za/
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