Paging System Sound Levels

Too Loud, Too Quiet, Just Right

It’s not easy to ensure that everyone hears the messages. The paging sound level shouldn’t be too loud or quiet; it must be just right. Selecting and installing IP paging speakers in buildings and outdoors is a science.

In schools, the paging announcements keep the staff and students aware of the schedule. In manufacturing and warehouses, announcements can notify the employees of shift changes. Sometimes, the paging announcements can be critical, such as a fire requiring a quick exit or an intruder causing a lockdown.

Here’s a comprehensive guide to selecting and installing paging speakers for optimal sound coverage:

The Science of Sound Levels for an IP Paging System

We measure sound loudness in decibels (dB), sometimes called the Sound Pressure Level (SPL). 0 dB is the minimum sound level a person with good hearing can hear. 130 dB is the point where the sound is painful. Even sound levels above 85 dB can be a problem. Most experts recommend using earplugs when continuously exposed to 85 dB and above.

The number of speakers must be determined based on all variables. IP-type speakers with built-in amplifiers are nice because they connect to the network and can be easily moved from one place to another.

Sound Versus Distance

The sound level decreases as you move away from the speaker. It decreases based on the inverse square law. Some calculators online can predict the sound level at a certain distance. You can also use a rule of thumb that predicts the sound level decreases by 6 dB for every doubling of the distance from the speaker.  For example, if the speaker provides 90 dB of sound at 1m (3.28 ft.), at a distance of 2 m (6.56 ft.), the sound level is 84 dB (90 – 6 = 84). For your reference, 96 dB is the sound of a power mower.

Sound Level Versus Power

The sound level from a speaker is directly related to the input power of the signal. The sound level will increase by 3 dB for every doubling of power. If a speaker is rated at 100 dB at 1-watt, it will provide 103 dB at 2-watt. If the power is increased to 4 watts, the sound level rises to 106 dB. Speakers also have a maximum sound level, so you can’t increase the power indefinitely.  

To learn more, read our article What is the Right Sound Level for Your Paging Speakers?  

Determining the Speaker Coverage

The speaker’s specifications include the effective angle of the sound level.

How to Calculate Speaker Coverage

The speaker coverage is calculated using the ceiling height, the distance to the person’s ears, and the angle of the speaker.  For example, let’s assume the speaker has an angle of 100°. We use a triangle to calculate the coverage distance (C). We first draw a triangle from the speaker with a 100-degree angle.

Split the triangle into two 90-degree triangles with a top angle of 50 degrees.

The distance from the speaker to the ears of the students is equal to the height (H) of the room minus the distance from the floor to the ears (L). If the room’s height is 10 ft and the distance from the floor to the ears is 4ft, then the distance to the ears (D) is 6ft. Now we can calculate the opposite side of the triangle using a right-triangle calculator. The side C/2 equals 7.15 ft, and C equals 14.3 ft. This is the speaker’s effective coverage area. Since the sound reflects off the floor and walls, in many cases, we get more coverage than the speaker angle predicts.

Paging in Schools:

As we have mentioned, the size of a room, the background noise level, and the height of the ceilings are all essential factors in determining the sound level that people hear. If you plan to use the speaker outdoors or near salt water, you will need a speaker that can work in that environment.

 There are several powered IP Paging Speakers available for schools. Schools usually have about 900 sq. ft classrooms and larger rooms such as auditoriums and gyms. The size of an auditorium can depend on the school’s population. For example, a 200-seat auditorium is about 3,000 sq. ft. They also have hallways that need to be covered by the paging system.

Classrooms can use ceiling-mounted speakers that fit in a drop ceiling. A few wall speakers can provide the right sound if there is no drop ceiling. A ceiling speaker with a sound level of about 80 dB will work if the room is quiet. If the classroom tends to be noisy, a ceiling speaker that provides 92 dB at 1 meter, at 1 watt, is better. An alarm clock about two feet away provides a sound level of around 80 dB.

The auditorium and gym require more speakers. The exact number of speakers and sound level depend on the room’s size and the ceiling height. Wall-mounted speakers can provide louder sound levels, but make sure no one is close to the speaker. You don’t want to hurt anyone’s ears. In a very noisy environment, such as a gym, you can select a speaker and amplifier that provides over 100 dB of sound.

Hallways can be noisy, so the speakers need to be closer together. Specialty speakers can be mounted on the walls or ceiling and provide sound in two directions.

To see some speaker suggestions, look at IP Speakers with Built-In Amplifiers.

Paging in Warehouses and Manufacturing

Manufacturing buildings can have high ambient noise levels, necessitating powerful horn speakers. Wall-mounted horns effectively direct sound over long distances, providing over 120 dB of sound.

Outdoor Paging Areas

Outdoor areas require weather-resistant horn speakers. The horn should be placed at least 13 ft. high so that the sound is not too loud for people close to the speaker. These speakers can be heard over 400 ft away.

Summary of How to Select the Right IP Paging System

The right speaker and sound level are essential to installing an IP Paging System. The right sound level ensures that everyone hears all the messages.  By carefully assessing your environment, calculating appropriate speaker coverage, determining the sound level in each location, and selecting a system that provides reliable paging announcements, you can establish a dependable system that ensures everyone hears critical announcements clearly and promptly.

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Please get in touch with us if you want help determining the speakers’ type and location. We can be reached at 914-944-3425 or use our contact form.