Whether you’re organising a local sports day, planning your wedding music, putting on your own gig or organising a festival, you need to know precisely which is the correct PA system to suit your needs. Before figuring out which is the right model for your event, let us take you through of the basics of PA systems.
What is a PA system?
First, things first, what even is a PA system and how does it differ to the HiFi system you’ve got in your living room? Well, short for ‘public address’, a PA system quite simply provides your audience with a constant quality of sound for a sustained period of time. Unlike regular HiFi or home speaker systems, PA systems are built to last. They’re far more durable, more powerful (yep, louder) and as a result, more expensive. They’re also designed (with the help of inbuilt or separate PA mixers) to receive and amplify multiple sources of sound – this means you can amplify a guitar, a vocal mic, a bass and a piano all at once.
How Do PA Systems Work?
Boiled down to absolute basics, an average PA system can be made up of the following components: microphone (or another source); mixer; amplifier and loudspeakers.
A microphone magnifies the volume of an audio source, transforming that sound into an electrical signal and feeding it into your mixer. They tend to fall within one of two categories:
Condenser Microphones: Condenser mics use their own power source and produce better quality signals but can be oversensitive and pick up excess background noise.
Dynamic Microphones: these are a little more durable than condensers. A common dynamic microphone is the SM58 vocal mic.
The microphone, along with all other sound sources, is plugged directly into the mixer. Roughly speaking, the mixer will have a number of channels for each source to plug into. It then provides the chance to mix multiple channels at different levels to provide the right balance of sounds; it may also allow sources to be separated in the mix by panning: e.g. a guitar could sound predominantly in the right speaker, with vocals in the left.
Often confused for the actual speaker, the amplifier’s job is to magnify the audio signal by manipulating its frequencies. This magnified signal is then sent straight to the loudspeaker for broadcast. Amplifiers are often built into mixers themselves, but will sometimes sit side by side.
The loudspeaker is where audio signals are converted into audible sound. Parts of a loudspeaker include a woofer (for low frequencies) and tweeters (for the highs). The protective grills at the front of PA system loudspeakers mean that they’re suitable for use in hot, sweaty rooms with users who are a few drinks down and not always in control of their lunges.
How Big A PA System Do I Need?
Deciding on how many watts you require in a sound system for your unique venue and purpose can sometimes seem like a dark magic to conquer. When reading the spec for a PA system, find out what the power is in Watts RMS (Root Mean Square). This isn’t as complex as it might seem at first: it basically means the measure of continuous power that an amp can produce or that a speaker can manage. The reason we look for Watts RMS is that you couldn’t maintain the alternative (Peak Power) constantly without damaging the system.
Handy tip: you shouldn’t run a PA system at full capacity because any peaks in the sound source may cause distortion. When choosing the right size PA system for your event, try to factor in whether you’re indoors or outdoors. When you’re outside, the sound produced has infinitely more escape routes and will not be reflecting off the walls of the venue, so you’ll likely need a far more powerful machine.
When choosing the right size PA system for your event, try to factor in whether you’re indoors or outdoors. When you’re outside, the sound produced has infinitely more escape routes and will not be reflecting off the walls of the venue, so you’ll likely need a far more powerful machine.
That aside, below is a quick guide which should help you figure out how many watts to lookout for when next choosing a suitable PA system for your event.
PA Systems: How Many Watts Do I Need?
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