The 15,700-capacity Stade Olympique de la Pontaise in Lausanne has been equipped with Nexo GEO S12 line array modules.
The 1950s-built stadium, which is used for football and athletics and can also stage concerts, urgently needed to upgrade its 30-year-old sound system in time for an International Athletissima athletics meet in July. It also needed to comply with the requirements of the FC-Lausanne Sport football club, based at the venue.
Philippe Martin from consultancy firm AER designed a stadium system comprising two identical set-ups on either side of the pitch, linked by a fibre optic Dante network. Each of the two grandstands has been installed with four clusters spaced 20m apart. Each cluster consists of five GEO S12 cabinets – four GEO S1230s and one GEO S1210, plus an RS15 sub, running in cardio mode. The clusters are each driven by NXAMP4x4 powered TDControllers, eight in total, with Yamaha MTX5D audio matrixes. The system was installed by local contractor Auditech, which designed special brackets to suspend the clusters, spreading the weight across the concrete roof.
Intelligibility was Martin’s main criteria when it came to designing the system. Working closely with Pierre André Aebischer from Nexo’s Swiss distributor ZAP Audio, Martin designed the system first in NEXO’s NS-1 proprietary design software before carrying out extensive simulation in EASE 3D acoustic modelling software. “We managed to get smooth, even coverage throughout the stadium,” he said. “There are no differences in level, the dispersion is totally homogenous as you walk around the stands.”
With the distance from speaker to seat no more than 13m throughout the stadium, the GEO S12's a tight dispersion pattern suits the speaker to this application. “Using the RS15 subs in cardio mode projects the energy 180º, keeping it in the area where it’s required and not allowing it to splash over the concrete and other hard surfaces,” explained Pierre André Aebischer from ZAP Audio.
A new fibre optic infrastructure was installed for the Dante network, chosen for its superior redundancy and compatibility with Yamaha matrixes. The Layer 3 network, providing simple connectivity and configuration, is installed with Luminex switches and linked by dual fibre, offering another level of redundancy. Each zone can be individually controlled, with sound levels muted or varied according to requirements, for example the broadcast press area on the lower level which needs lower SPL. The entire system is symmetrical, with an amp room on each side and two control rooms, one for football and one for athletics. "It was important to have symmetry in the design,” says Martin. “With Dante, it is easy to position the control room in any location in the stadium.”