Acoustic consultants AMS Acoustics, had already implemented an earlier first phase upgrade last season to bring three stands into VA compliance. During the course of this exercise the capture of a full range of measurements was required and the resultant data, after analysis, was used as the cornerstone for an entirely new design the following year.
During the short close season AMS returned with ETA Sound to implant a complete Harman Pro solution, using a fibre-based signal network that would extend to the three main stands - the North (James Hargreaves) stand, the East (Jimmy McIlroy) stand and South (Bob Lord) stand.
The West (David Fishwick) stand is under review with the expectation that it will be replaced; this will in effect form part of a Phase 3 system enhancement (along with the back-of-house areas) for which cabling has already been implemented.
Tasked with supplying a voice alarm-compliant system, with high STI (Speech Transmission Index) AMS Acoustics' project designer Helen Goddard made her product selection with care. Reverberation (RT) and audio communication times within the stadium (along with certain modelling data of the stands), had already been plotted by AMS Acoustics, who believed that having worked successfully with the JBL AE loudspeakers in the past, they would again meet the remit.
The company needed to achieve peak level in an emergency scenario, related to crowd noise. "We knew the system would have to achieve a maximum of 102-105dB(A) and this meant we needed to use loudspeakers that would be able to achieve these kind of levels without going into compression."
First the JBL loudspeakers were set a number of challenges - including a performance evaluation in AMS Acoustics' anechoic chamber, even to the point of a destruction test. This was supported by Sound Technology, the Harman Pro distributors, who provided all the necessary back-up.
The acousticians then set about designing the control, signal path and zoning matrix, opting for an integrated Harman Pro package based on system optimisation and cost-efficiency. "As the budget was quite tight this was the logical way to go," stated Goddard.
Crown CTs amplifiers, fitted PIP-USP3 speaker processing units, BSS Audio Soundweb London DSP devices, with BLU-link, running on a fibre backbone - and independent HP ProCurve network switches across all rack locations - form the system architecture. In this fully-redundant design, UPS systems provide all the power conditioning and mains support in the event of a power failure.
The installation was also notable for the advanced DSP programming skills of ID Networks' Martin Barbour, using the attributes of Harman Pro's new London Architect v2.06 and System Architect v2.00 software - the latter being its first use anywhere in the world. "Given that this was a fast fit job it saved me huge amounts of time," he said.
(Jim Evans)
