Last summer, Croke Park Stadium in Dublin completed its programme of design and installation of a permanent PA/VA sound system. This iconic sporting venue is the national stadium of Ireland and home to the Gaelic Athletic Association (GAA), and it has been at the heart of Irish sporting life for over 100 years. With capacity for 82,300 people, it is the third largest stadium in Europe (behind Camp Nou in Barcelona, and Wembley Stadium in London).

Mongey Communications, the full-service AV and communications provider from Kildare, has been involved with Croke Park for 15 years, and was instrumental in guiding the GAA to a world-class audio set-up.

The bowl sound system design options, done in accordance with relevant British Standard guidelines and industry-standard practices, looked at the reinforcement of live and pre-recorded entertainment audio during sporting events, audio reproduction for video content, and reinforcement for pitch-side interviews.

In addition to improving audio throughout the stadium, the brief required the new system to have the capability to supplement coverage for concert use. Visiting productions can now tie into the Croke Park house system to deliver the best possible results for the upper seating levels in the Hogan, Cusack and Davin stands.

The stadium roof canopy now carries 18 clusters of NEXO’s GEO S12-ST specialist long-throw loudspeakers, each curved cluster containing 8 modules. Powered by NEXO’s proprietary NXAMP4x4 amplifiers and controlled over a Dante network, the new system addresses the three grandstands of Croke Park. The 18 identical clusters give uniform coverage across all seats, and significant improvements in SPL without infringing the very stringent noise regulations applied to the stadium’s events. The fourth side of the stadium, known as Hill 16, is maintained as traditional terraces and has a discrete audio system.

NEXO’s compact 2-way GEO S1210-ST is a high-output, long-throw version of the standard GEO S1210 cabinet, and has been optimised for stadium installations. It offers exceptional SPL for long-throw applications, with enhanced speech intelligibility. The module displays exceptional MF/LF output (105dB SPL nominal sensitivity) from a single 12”, using NEXO’s proprietary Directivity Phase Device.

The GAA’s criteria for the audio upgrade focussed on qualitative improvements to the stadium facilities for voice alarm and evacuation (VA), and for announcement and music reinforcement for matchday entertainment (PA). “The audio system in the stadium was in the region of 20 years old. Technology moves very quickly and certainly we were very conscious that it was time for us to pay attention to the improvements made in technology, as regards playing music and speech intelligibility,” explains Brian Conlon, Head of Stadium Operations & Projects.

The GAA’s stated goal of equipping Croke Park with the highest international level of technical facilities, allowing them to attract the finest performers in the world, required a well-researched supply chain. Mongey and Vanguardia refined their choices down to three different suppliers, focussing on the issues of price: performance ratios, the manufacturer’s ability to deliver, and engineering issues such as the number of loudspeakers necessary to do the job.

Croke Park’s amplification hubs had been already been upgraded and 8km of electrical cabling installed. London company RG Jones were tasked with rebuilding of all the Croke Park racks and doing all the cabling from the marshalling boxes back to the NEXO NXAMPs, together with the power distribution and cabling to route the controlling Dante network straight into the amplifiers.

The job of installing nearly 150 NEXO loudspeakers had to be fitted into a frighteningly small window of opportunity, bracketed between a Rolling Stones concert and the Gaelic hurling and camogie championships.
“We had 2 weeks for the physical installation work,” continues McGrath. “We created the sub-assemblies, fixed into custom-built steel frames. Given the height of the roof canopy and the weight of the loudspeaker clusters, the only way to do it was to send the riggers onto the top of the roof to haul the arrays up into place. With all the wiring done from the top side of the canopy, they were then bolted into place under the roof structure, which had been modified with special steelwork to hold them.”

Astonishingly, the Mongey team completed the installation of all 18 clusters in less than 2 weeks, allowing another week for finetuning the network, and testing and commissioning the system.

With the advantages of the Dante network, the stadium can now deploy pitch side mixing positions very easily, depending on the entertainment content.

Audio quality has been vastly improved and bears favourable comparison with international best-in-class standards. In addition to meeting the required life safety standards in full, the new equipment provides very high-quality public address for general announcements. Reinforcement of live and pre-recorded entertainment audio during sporting events and audio reproduction for video content has been deemed exceptional, and commentary and feedback on both pitch-side interview and concert audio reinforcement has been universally positive.