ARUP system designer, Paul Malpas reports, "The biggest challenge was the difficulty of getting access to loudspeaker mounting positions in a live stadium. Harman provided a lot of assistance directly to us by providing specific data, interpreting the catalogue data and helping with the acoustic modelling effort."
Faced with the added constraint of a tight timescale, ARUP's final design needed to satisfy both British .5STI and 101 dBA SPL standards for stadia and the club's urgent need for clearer announcements. Malpas adds, "Our involvement was because the main speaker system from the roof was not quite achieving the speaker intelligibility requirements of an emergency system and that's obviously key in a football stadium."
ARUP, working closely with Harman Pro and Xtralis (Vision Systems), suggested two possible loudspeaker solutions including a JBL PD5212-WRC weatherproof loudspeaker system which was chosen for the final design.
Driven by Crown IT4000 series amplifiers and administered via Millbank's existing VxLan network and touch-screen paging system, the installation included a total of 34 loudspeakers. JBL PD5212/95 speakers were positioned around the arena at intervals of 15m with three additional PD5212/64 speakers used for precise coverage at each of the corners. The old under balcony 10w horn speakers were replaced with JBL Control 25T units to ensure equal clarity in the crucial balcony area where the director's area is situated.
Eddie Thomas, project manager and consultant at Xtralis adds, "We tried a number of different loudspeakers in the environment and none of them performed as well as the JBL. We've been using those speakers at the O2 arena as well. Harman were good about this because we had a very tight timescale in which to get these speakers up. We had them flown in within about four weeks from order which is quick really for getting a bespoke speaker made up."
(Jim Evans)
