In this article, we will be looking at the basics of what to look for in a PA sound system. We will be discussing some of the terminology you will hear and try to make it easy to understand what the various terms mean to you.
A PA (public address) system comes in many shapes and sizes depending on the application. Obviously a larger system is used in a concert hall than would be in a small room. A basic thing to consider when looking at purchasing or hiring a PA sound system is the primary use.
Speaker Power Source – There are two basic types of speakers. Passive and active. A passive speaker (also referred to commonly as an unpowered speaker) is essentially a speaker in a box (cabinet). It is incapable of producing any sound by itself. It requires an amplifier to feed the signal to it. The other option is an active (also called powered) speaker, which includes the amplifier integrated into the same box.
Speaker Size – Speakers come in various sizes. The size of a speaker is referred to in inches and it is taken by measuring the diameter of the speaker cone. Common sizes are 8, 10, 12, 15 and 18 inch. Generally, the larger a speaker, the better the bass response, however speaker quality also plays a major role in the overall sound of the speaker.
The Mixer – The mixer part of the PA system is where you "plug-in" your audio source (whether it be musical instruments, microphones, iPods, turntables etc). The mixer is where you are able to control the volume of each individual audio source. These are called channels. For example a 4 channel mixer is capable of receiving four audio lines. Many mixers also come with such things as graphic equalizers, on board effects (such as reverb or echo) etc. Mixers can be either powered or unpowered. The type used depends on the type of speakers being used. A powered mixer has an amplifier integrated meaning that it is handling the power output to the speakers, whereas an unpowered mixer does not have an amplifier allowing the speakers to handle the powering themselves. Don't be confused though, both types of mixers still need to be plugged into electricity to operate, it's only the speaker power that is being referred to and not electrical power. So, if you have a powered mixer, you match it with unpowered speakers. If you have an unpowered mixer you will need powered speakers.
Speaker Power – PA system power is measured in watts. The higher the watts are, generally the more powerful the system is. You will commonly find a number along with a letter 'w' to indicate the number of watts that are being delivered by the system.
We hope this article has helped you to become more familiar with some of the things you need to look for when considering a PA sound system for yourself.