As incumbent maintainers and installers of the PAVA Systems at the ICC Birmingham, BL Acoustics were engaged to further upgrade the Voice Alarm systems for the newly refurbished Symphony Hall.
The specification required high-performance Music Routing for the Performance Spaces and Bars by utilising the existing sound systems where possible.
Music was routed via the Bosch Voice Alarm system using Symetrix AV Processing Controllers.
For the main Performance Space, we installed four HK Audio VORTIS 2 EN54 rated Loudspeakers providing a powerful & superb quality sound in combination with the Bosch Praesideo Voice Alarm Amplification.
Fourteen music inputs were distributed throughout Symphony Hall providing a great deal of plug and play flexibility with the Symetrix System routing any input to any output.
Input panels were constructed using the single gang MK Edge Brushed stainless panels as the standard. We would implement the use of two types of panels; one would have a single XLR input and the other a 3.5mm mini jack input.
Flexible Control
The Symetrix ARC-3 Control Panel provided simple control of each input panel/music source to multiple zones throughout the Symphony Hall Foyers and Performance Spaces.
Design Verification & Modelling
The expansion included the fitting of new bars in each of the lobby areas on Levels 3, 4, 5 and 5A, a new performance space and 2 hospitality rooms on level 5A.
As part of the project, we were commissioned to design and install voice alarm coverage to the acoustically unique space, specifically the performance area with its high open ceilings and full length glass exterior wall which presented significant challenges to intelligibility. Being integrated with the Voice Alarm system, the project specification necessitated the use of EN54 approved loudspeakers only.
Before we could commence physical works, Computer Simulated Modelling of the prime areas for new coverage needed to be carried out to give evidence of design and to plan the equipment and cabling requirements. A computer model (Catt Acoustic 9) was used to create the three-dimensional environment which was then compared in performance to the specified requirements.
Specification
The specification gave a target of band ‘G’ 0.48 STI or better for 80% of the area exceeding 85dBA.
Reverberation
Our model implemented surfaces that were approximated to the surface types used in the building. These would provide prolonged activity for sound in terms of reverberation. We distributed the reflective and absorptive surfaces accordingly and checked the reverberation levels were in line with what would be expected for the space.
The Model
Our Catt model was a complete model of all areas. This enabled us to model a large number of options, should they be required. The model was run several times to see the most optimum position and direction of the speakers.
RESULTS
Proposed System Performance
As stated in the specification, the system was expected to meet band G in 80% of the spaces. The most acoustically challenging space, as afore mentioned, was the performance area. Here, we specified 4 high power cabinet speakers capable of delivering the sound pressure levels and performance required to give clear coverage across the atrium.
For the Hard of Hearing
The Performance Space on Level 4 was fitted with a large 16m x 12m Seven Segment Induction Loop powered by UNIVOX Audio Systems. This was installed beneath the oak floor so as to be undetectable. An audio feed was provided to the loop from the PAVA rack BL Acoustics were installing in Hall 2. This would enable both audios from the Performance Space systems and from the Emergency PAVA to be transmitted onto the loop.
Completion
The installation exceeded the clients’ expectations and offered a massive cost saving by utilising much of the already existing amplification and loudspeakers.
