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.
B L Acoustics are proud to add another notch to our belt, having successfully completed the replacement of the public address and voice alarm systems at the (formerly named) Arena Birmingham. The old systems were replaced with Bosch Praesideo EN54 compliant systems communicating via a site-wide optical network installed and designed by BLA.
Utilita Arena Birmingham is an indoor arena and sporting venue with a capacity for 15,800 people. Each year (excluding lockdown), the venue hosts over 100 live events and welcomes half a million visitors through its doors. In 2018 the venue underwent a major renovation with remodelling of the concourse areas and public realm.
A site maintenance visit highlighted several issues with the site’s PAVA system. The main issue was the lack of audibility in certain areas during an evacuation, particularly the main concourse area. The audibility problems were caused by a combination of high noise levels from the smoke extract fans and unsuitability of the loudspeakers installed as part of the renovation project
B L Acoustics have been maintaining the systems at the ever-developing site for many years which helped us to acquire substantial site-specific information which proved to be valuable throughout the complex installation. This benefit enabled us to recognise that maintenance visits before 2019 continued to report existing and new issues across the system with some components beyond their recommended life.
Our Proposal
A solution was designed for the problem areas and modelled using acoustic modelling software. More suitable loudspeakers and an improved layout was proposed and installed to produce much improved audibility even when the smoke extract was running. The increased power requirements of the new loudspeaker layout design had an effect on the rest of the system as higher power loudspeakers require more amplification, and more amplification requires higher capacity battery support.
Our proposal offered replacement equipment which would have the capacity to support the improved loudspeaker coverage throughout the building. This would include the installation of a new high integrity fibre cable network between each of the equipment locations. As well as changing the loudspeaker layout in the concourse areas, each voice alarm loudspeaker across the site was upgraded to new EN54 variants.
During the operation of the aforementioned fans, the SPL level would need to be a substantial level, which would be too high for normal PA announcements. The system includes for ambient noise sensing in the concourse areas to allow the full potential of the system to be used when the fans are operational but keeps PA announcements at a comfortable level during normal operation.
One of the major priorities our client expressed was that the systems could remain in full use throughout the replacement process. The venue is an extremely busy one, meaning that downtime of the system would have been unacceptable and hazardous to life safety.
System Replacement
The completed project was a result of thirty days/nights of work, involving multiple phases of installation, commencing with the fitting of a new resilient loop in fire-rated cable across the site. To ensure the site remained operational throughout the installation process, temporary audio and control links were fitted between the new and existing systems so that both systems could operate concurrently while circuits were switched over from the old system to the new.
Microphone Panels
The old system had both emergency fireman’s microphone and paging microphone units located in various positions throughout the site. B L Acoustics provided replacement units and in the case of the fireman’s microphone provided re-engineered panels which were custom-built to fit their location.
Loudspeakers
Choosing loudspeaker types was critical to the project with tight specifications to provide key criteria:
– EN54 Compliance
– Acoustic Performance
– Aesthetics
– Programme Windows
All loudspeakers were replaced to meet the latest EN54 standards; compact Bosch ceiling loudspeakers were utilised in most areas.
