London-based electronics engineering company PEL Services was commissioned to design and install upgrades to the public address and emergency sound systems at Celtic FC’s 60,000-seat stadium Celtic Park.
With a stadium-wide IT network and existing public address infrastructure already in place, PEL advised the selection of Bosch Praesideo digital Public Address and Emergency Sound System with Electro-Voice pro audio loudspeakers to improve coverage, clarity and fidelity within the main bowl area of the stadium.
Because both systems can be interfaced to the Dante networking standard, the Bosch Praesideo system and all Electro-Voice loudspeakers are monitored and controlled remotely via Electro-Voice N8000 NetMax digital matrix controllers.
Vic Swain, engineering director for PEL, says: “The club wanted a state-of-the-art emergency notification system, and wanted to integrate that with an audio system that would provide clear sound for every seat in the house. It’s a challenging project, but the combined solution of Bosch and Electro-Voice works perfectly.”
The first phase of the operation was the installation of the Bosch Praesideo public address and emergency sound system, serving what Swain refers to as the “back of house” area: the internal portions of the stadium, including concourses, turnstiles, restrooms, and offices. Its open architecture and high level of redundancy makes Praesideo a scalable, reliable solution that exceeds safety standards while offering complete communications flexibility.
The stadium system is based on dual Praesideo network controllers with an audio expander interface and six strategically placed call stations. The 100V audio system utilizes legacy installed loudspeakers, all of which were tested and upgraded with Bosch line supervision sets. This enables Praesideo to check all speakers for proper line operation. The system is powered by 22 Bosch power amplifiers with onboard DSP modules.
PEL engaged Acoustics Plus, an independent acoustic consultant based in Croydon, to advise on proper deployment of the Electro-Voice loudspeakers. Research included recording SPL levels throughout a game, documenting the sonic requirements and using computer modelling to map optimal locations and dispersion patterns for full coverage. Aimed down from beneath the roof, the system uses a mix of frontloaded EVF-1152D and horn-loaded EVH-1152D, both full-range, weatherized loudspeakers from the EV-Innovation family.
“Celtic always wants to do the very best for their fans – in addition to meeting the evacuation system legal standard for Speech Transmission Index,” notes Swain, “they also wanted it to sound just as good when the place is really rocking during a big match. These EV speakers accomplish that with ease, even in problem areas. We had structural engineers and riggers working closely with the acoustic consultant to make final adjustments. A lot of preparation, but on the day the speakers were hung and aimed, it was extremely quick and accurate.”
As part of the process, Electro-Voice CPS series power amplifiers, two N8000 NetMax DSP matrix units, and a redundant fibre ring were installed as infrastructure support for the full stadium system. To date, the new loudspeakers are in place above the north stands and adjacent corner areas. Future phases will complete the installation above the south stands, adjacent corner areas, and west and east stands behind the goals.
“The integration of Bosch Praesideo in the back of house with Electro-Voice loudspeakers aiming at the area above the seats, all working together in a centrally controlled network, represents a real commitment to the safety and comfort of the fans,” he says. “It’s great to help a legendary organization like Celtic F.C. to achieve their goals.”