- Loudspeaker
A loudspeaker or speaker is an electro-mechanical device that converts electrical energy into mechanical motion that may be heard as an audible signal. In the context of fire safety systems, a loudspeaker is used within an occupant warning system or emergency warning system used to distribute warning signals and audible messages to the occupants of a building in the event of a fire or other emergency.
Types of Loudspeakers
Emergency warning systems rely on various types of loudspeakers to deliver clear, intelligible messages throughout different environments within a building. The selection of speaker type depends on acoustic requirements, building layout, environmental conditions, and compliance with Australian Standard AS 1670.4.
- Recessed Ceiling Speakers
Installed flush into the ceiling, these speakers are designed for areas with suspended ceilings and are common in offices, retail spaces, and corridors. They provide wide sound dispersion and are ideal for evenly covering open indoor areas. - Surface-Mounted Wall Speakers
These speakers are mounted on walls where ceiling space is limited or inaccessible. They are commonly used in stairwells, plant rooms, and areas with hard ceiling finishes. - Horn Speakers
Horn speakers produce high-output sound and are suited for noisy environments or large open spaces like warehouses and factories. They focus sound over greater distances with higher intelligibility in challenging acoustic settings. - Weatherproof/Outdoor Speakers
Designed for external areas or environments exposed to moisture, dust or temperature extremes. These speakers are rugged and meet relevant ingress protection (IP) ratings for outdoor use. - Ceiling-Mounted Pendant Speakers
Suspended from the ceiling, these are used in buildings with exposed structures or high ceilings where traditional ceiling speakers cannot be installed. They offer broad sound coverage for open-plan environments, such as warehouses.
Each speaker type must be selected and installed to meet the minimum speech intelligibility requirements specified in AS 1670.4 and performance requirements of AS 7240.24 (Fire detection and alarm systems – Part 24: Sound-system control and indicating equipment).
A critical consideration for loudspeakers in emergency systems is speech intelligibility—the clarity with which spoken messages can be understood. In accordance with Australian Standard AS 1670.4, which governs the design, installation and commissioning of emergency warning systems, speech intelligibility is essential for ensuring that voice announcements can be clearly understood across all occupied areas of a building. This helps to reduce confusion, improve response times, and ensure the safety of occupants during evacuations or other emergency responses1.
- 1
AS 1670.4:2018 – Fire detection, warning, control and intercom systems – System design, installation and commissioning – Emergency warning systems.