The resulting system, designed and controlled using Harman HiQnet System Architect features components from Harman Professional brands including JBL, Crown and BSS Audio.
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 closed 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.
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. Her design enabled the voice evacuation system to double up to meet on-pitch entertainment requirements. 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," Goddard explained.
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 Professional UK distributor, 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 Professional package based on system optimization 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 fiber backbone - and independent HP ProCurve network switches across all rack locations - form the system architecture. Media converters are provided for the BLU-link data and HP GBICS-LC, providing fibre interfacing on the HP ProCurve switches, and the infrastructure provides one dual redundant Ethernet network as well as an independent ring for the BSS AUDIO BLU-Link audio transport.
Eddie Thomas of ETA Sound worked closely with Tom Williams, Sound Technology's acoustician. In fact the latter had been closely involved from the outset of the project - taking part in the initial concept discussions with AMS Acoustics, supporting the equipment testing and measurement procedures, setting up the load monitoring - and finally assisting with system commissioning.
In total, 16 JBL AM6315/95 (90° x 50°) full-range loudspeakers with rotatable horn and 12 AM6200/95 mid/high loudspeakers have been used.
(Jim Evans)
