Choosing the right PA system for you

However awesome the gear you’re using, and however tight your band is, if you don’t play your music through a decent PA system, it won’t sound good. You need a system that offers sonic clarity, as well as enough volume for everyone in the audience to hear every last detail. In this article, we’re going to help you navigate the murky world of live sound systems and give you some tips on how to make the right decision, whether this is your first PA system or you’re upgrading that old pair of boxes you’ve been using for the last 45 years.

What is a PA system?

On the most basic level, a PA system exists to get the sound from you – the performer – to your audience. There are a few different ways to get this done, but the fundamental components perform these specific jobs:

• Turning acoustic sounds into electronic signals
• Mixing these electronic signals together and applying effects
• Making the signals louder via an amplifier
• Sending the sound through speakers

Generally, these jobs are done by a combination of one or more of the following components:

• Microphone: this converts acoustic sound (such as your voice) into electronic signals that can be processed and amplified. Microphones can be wired (you need a cable to plug it into the mixer) or wireless (the microphone will transmit the signal wirelessly to a receiver, which itself is plugged into the mixer)
• Mixer: this allows the various signals (from microphones, keyboards etc.) to combined and their individual volumes to be set. A mixer can be a separate unit or be built into e.g. the speakers
• Power Amp: this boosts the volume of the signal coming from the mixer. Again, it can be a separate unit (feeding “passive” speakers) or can be built into the speaker itself
• Speaker: the speakers effectively vibrate in such a way as to cause the air to wobble more or less, causing your ear drums to wobble, and your brain to perceive sound. In general, the larger the speaker and the more force is used to wobble the air, the louder the sound! Speakers can vary in size from the speaker on your phone to huge multiple speaker configurations as seen at major venues such as Wembley Stadium.

The way all of these components are combined varies between systems, and those systems will have a range of different functions and capabilities designed for different purposes. To identify which system is right for you, you’ll need to ask yourself the following questions:

• How loud do I need the system to be?
• How many instruments and / or acoustic sources do I need to amplify?
• How portable do I need the system to be?
• What additional features do I need?

We’ll tackle each of these questions separately:

How loud do you need the system to be?

Loudness is a function of power: on a simplistic level, the more powerful the amplifier, the louder the output. There are considerations around the efficiency of the amp and the headroom (at what point the output will become distorted) but to get a broad idea of how loud a system will be, you can assess the power of an amp (or a speaker with built-in amp) by looking at how many watts

The power of amplifiers is measured in watts. To give you an idea, the following explains about how much wattage you’ll need for different scenarios:

• Pub acoustic gig with singer and acoustic guitarist: 100-200 watts
• Small venue gig with jazz band: 300-800 watts
• Medium venue gig with rock band: 1,000-2,000 watts
• Big venue gig: 5,000-10,000 watts
• Stadium gig: 25,000 watts and up

However, this is just a rough guide; different venues will respond differently to different wattage levels, and e.g. outdoor gigs will need a lot more power to generate the same sort of loudness.

It’s also worth noting that if you are buying a separate amp, you will need to leave some headroom between the output of the amp and the capacity of the speakers. In practise, a good rule of thumb is to ensure your amp has twice the wattage of your speakers. So, for example, if you want a total output of 500 watts, you should use an amplifier that is rated at 1,000 watts.

One way to completely avoid the worry about which amp will match which speakers is to buy active speakers where the amp is built in to the speaker itself. In general, unless you need to be able to control the amp from a different location to the speakers, we recommend these sorts of systems.

How many instruments and / or acoustic sources do you need to amplify?

If you’re just going to be sticking an acoustic guitar and vocal through the PA system, you don’t need many inputs (theoretically you could get away with two!). However, it’s always good to future proof your system; might you have a backing vocalist at one point, or will you need to mic up some percussion? Always get a few more channels than you think you’ll need!

How portable do you need the system to be?

This is the big question. Are you going to be lugging the system around regularly, or is it going to be fixed in place? Often there is a trade-off between portability and sound quality. All-in-one systems (that include speakers, amps and mixer in as few separate units as possible) are easy to move about and easy to set up, but are not as versatile as systems with separate components.

In general, for bands, solo artists, or small venues, it makes sense to go for active speakers (those with amps built in), so the decision is more about the sound quality you need (which, understandably, increases with price) and the form factor.

The most basic PA set-up is a mixer feeding a pair of active speakers, and this will do the trick for most small venues, and can fit in the back of a car. You can browse our mixers here, and our range of PA speakers here – we have found the most consistently reliable and best value speakers to be those from Yamaha and Mackie. Most of these options also have very basic mixers accepting a couple of inputs built into the backs of the speakers themselves, so if you’re just amplifying e.g. a guitar and vocal and are playing a small pub, you can get away with just taking a speaker along.

If portability is a major issue, check out our range of full PA systems here. You’ll notice that amongst the PA systems are some strange column-like structures from RCF and LD Systems. These are a fairly recent innovation that take portability to a whole new level as they feature multiple small speakers housed in thin columns that, thanks to advances in technology, still offer a great amount of volume.

What additional features do you need?

PA companies are regularly trying to outdo each other with the range of bells and whistles that they feature, the most useful being Bluetooth connectivity, which allows you to stream music from a portable device such as an iPhone, and can also allow you to tweak settings such as EQ.

Conclusion
Buying a PA system can seem like a daunting prospect, but really it’s all pretty simple, as we hope we’ve demonstrated in this article. If you need any advice whatsoever or want to audition some systems in a relaxed environment, give us a call or drop by one of our stores.