Technology: Public address and voice alarm systems
Technology: Public address and voice alarm systems
We spoke with Ralph Singer from TOA Electronics and LDA Audio Tech’s Juan Manuel Díaz and Pedro Martos about the importance of a good PA/VA system
What is a PA/VA system?
Juan Manuel Díaz, LDA engineering and support manager: A public address and voice alarm (PA/VA) system is an electro-acoustic system to manage live and pre-recorded messages. It can be used as an information or entertainment system, as well as a voice evacuation system. The standard composition is: input sources, management matrices, amplifiers and, finally, speakers.
Ralph Singer, sales and marketing director at TOA Electronics Southern Africa: A PA/VA system usually consists of the headend equipment which is made up of a system manager incorporating the mixer, digital signal processor, amplifiers, power supply managers, microphones (fireman’s and remote microphones) and a variety of certified, fire-rated speakers. Included in the system manager are additional features such as monitoring of the entire speech path from microphone capsule to the speaker lines, control inputs and outputs for integration with fire detection panels and other third-party products. Backup batteries are added to the system in order to ensure functionality in the event of a power failure. The TOA VX-3000 also has a built-in ambient noise controller so it is possible for the system to automatically adjust the volume levels as a house of worship gets noisier or quieter due to the number of worshippers differing during services.
Do PA/VA speakers differ from other speakers?
Singer: Yes, they do. Speakers for emergency purposes are required to be certified according to the fire standards (EN54 or British Standard) and usually include a thermal fuse, porcelain connector block and fire-resistant internal cabling. The speakers function as normal speakers do and therefore can be used for multiple purposes. TOA manufactures a wide range of certified speakers, including line arrays, cabinet, ceiling, projection, pendant and horn speakers.
Pedro Martos, LDA international sales manager: They could look similar once they are installed, but the speakers used for emergencies must meet minimum standards of stability, water tightness and availability, following the applicable regulations – in our case, EN54-24. In addition, these speakers usually have a better frequency response in the specific range for the human voice, sometimes ignoring lower and higher frequencies. Another particular feature of these emergency speakers is their high directivity, to avoid unwanted reflections, thereby improving the intelligibility of the system.
Can a PA/VA system also perform other functions?
Singer: Yes, this is possible. TOA has had many of its speakers, including array-type, certified in order to provide cost-effective solutions for the various users, including houses of worship. Alternatively, it is possible to integrate the two different systems, should this be the case, whereby the voice alarm system also uses the speakers within the existing public address system. One has to be careful as usually the existing speakers are not fire rated, so it would be best to add some fire-rated speakers as well.
A voice alarm system incorporates a public address system and a BGM (background music) system. The PA system can be used to address worshippers as normal when a service takes place, can play background, or even foreground, music (especially if there is a live band) and can be used for emergency purposes in the event of an incident (fire, natural disasters and even shooting incidents) and is therefore able to provide a complete solution.
Mosques are able to use voice alarm systems as a PA system and for the call to prayer. This is ideal for supersized mosques, as there are usually many thousands of people crowded inside. Should there be an incident, the voice alarm system can be used to guide the worshippers to safety.
Martos: An LDA system can be used as a PA and VA solution at the same time. Electro-acoustic systems can have a double use. Several speaker lines can be installed in a mosque and used for the call to prayer. In the majority of cases, outdoor horn speakers are installed to fulfil this need.
Díaz: PA/VA systems can be used for any type of music and messages, such as announcements and BGM. You can also use them to perform other operations, such as opening doors, controlling lighting or any other automated processes. Our equipment can be easily integrated with other systems: cameras, CCTV circuits, central servers and more. They offer a lot of additional functions, like integration with a building management system or remote control using a web browser. And, above all, voice alarm systems can save lives.
What should a house of worship look for?
Díaz: First of all, you have to consider the word intelligibility, or speech clarity, and, depending on the size, a phased evacuation. Another factor to consider is fire resistance – not only for the speakers, but also for the wiring and other equipment. The emergency activation has to be easy to reach and be located where there are always people who are familiar with the evacuation protocol.
Singer: The system must be scalable, provide digital signal processing in order to adjust the sound to meet the acoustic requirements of the building and must be easy to operate.
Ideally, PA/VA Systems should be designed, taking multiple factors into account: the size and layout of the building, the finishing touches (for example, are there curtains or exposed windows?) and the acoustics of the building (houses of worship usually have very poor acoustic environments due to high ceilings, lots of open spaces, many windows, hard finishes such as tiled floors and wooded benches, and many more factors).