How to Choose Loudspeakers for a Voice Alarm System

The loudspeaker is the “last metre” of any voice alarm system — it is the component that decides whether people actually hear a message and understand it. Choose the wrong type or put it in the wrong place, and the whole project falls apart: speech either drowns in background noise or dissolves into booming echo. And the right choice doesn’t start with a model number or a price tag — it starts with the site and the job the system has to do. The same sound behaves very differently in an office with a suspended ceiling, on a noisy factory floor and across an open yard. This guide walks through how to choose loudspeakers for voice alarm on a specific site: the types available, the specs that matter, and how to estimate the quantity you’ll need.

Which loudspeaker should you choose for outdoor areas?

For open sites, perimeters and noisy production halls, a horn loudspeaker is the natural choice: it delivers a high sound pressure level and carries an IP66 ingress protection rating (outdoor equipment in general is rated IP65/IP66). Where a large, reverberant open space also demands clear speech, column loudspeakers are the better option — they hold speech intelligibility over longer distances.

How does a ceiling loudspeaker differ from a wall-mount one?

A ceiling loudspeaker installs into a suspended ceiling and provides even, overhead coverage across the floor below. A wall-mount loudspeaker is used where there is no suitable ceiling, or where you need sound aimed directionally at a particular zone; where music quality matters too, wall-mount loudspeaker systems are the way to go.

What does a 70/100V line mean and why do you need one?

This is a high-voltage distribution line. Dozens of loudspeakers connect to it from a single amplifier, and the cable can run for hundreds of metres with minimal losses. The power drawn by each unit is set by the tap selected on its matching transformer.

How do you work out how many loudspeakers you need?

As a rough guide, size ceiling units by floor area and ceiling height, wall-mount units by the length of the zone, and horn units by throw distance. Then check the total load on the line against the amplifier’s rated power. The fastest way to run these numbers is our online selection calculator.