How to Design a Public Address System

A public address system allows you to broadcast information to a large group of people, whether you are giving a speech or playing live or recorded music. However, it takes more than a microphone and a speaker to design a good public address system. There are other aspects to be considered, such as dynamics, quality of equipment and safety. This article will explore what it takes to design a good public address system.

Things You'll Need

• Blueprints
• Applicable electrical wiring
• Power generator (optional)
• Safety tape

Instructions

1. Consider the size of the crowd you intend to address. Having a large system for a small number of people can require extra time or electrical power that isn't necessary. Using too small a system for a large crowd may reduce the efficiency of your public address system. For example, you may have to turn up the volume so loud that your broadcast becomes distorted. Compare what's used in other venues that are similar to yours to get an idea of how large a system you need.

2. Ensure all the equipment you plan to use can be sufficiently supported by the wiring in the room. Public address systems often use a lot of wires and plugs that can take up numerous outlets at varying wattages. If the venue has old wiring, you might want to consider either changing venues or using a back-up source of power such as a generator.

3. Select the proper equipment for the general use of the public address system. Most of the standard equipment includes a microphone, a set of speakers, a soundboard and an amplifier. However, the specific equipment you choose depends on your intended use. If you are using an outdoor venue or one with high humidity, dynamic microphones may be needed because they tend to be more rugged. For solo speakers or small acoustical set-ups, condenser microphones tend to produce a purer sound. You may only need an 8-channel console for a small set-up, or a 64-channel mixing console for live bands.

4. Create safe pathways for all related wiring and equipment. Wires connecting the microphones to the soundboard should generally be out of the public's way and long enough so the user can move around. Power plugs and other connecting lines should run to the consoles either through the ground or the ceiling so that people won't trip and fall. Speakers and monitors should be placed securely so that they won't tip over at the slightest touch or bump. If you can't go without running exposed wires on the ground, tape them down securely and mark their path so that it can be seen even in the dark.

5. Complete several sound checks once all the equipment is set up. Sound checks should involve listening to the address from several different points in the area while the broadcaster plays at the same volume. The quality of sound should be clear and crisp from the front of the room to the most extreme listening position. Reverberation and echoes should be eliminated. For versatile use, sound checks should be done with recorded music, live music and live public speaking. This will allow a console operator to know what needs to be adjusted for each use.

Tips & Warnings

• Failure to account for electrical ratings when setting up a public address system can result in electrical shock, injury or death.

References

• System Design Tips

Resources

• Read this Article in Spanish
• PA System Experts