In this article, we discuss how to set up a stage sound system (PA system).
What is a PA system?
When we speak of a sound stage system we are in general referring to a PA system.
A PA system is “A public address system (PA system) which is an electronic system comprising microphones, amplifiers, loudspeakers, and related equipment.
It increases the apparent volume (loudness) of a human voice, musical instrument, or other acoustic sound source or recorded sound or music.
Where are PA Systems used ?
PA systems are used in any public venue that requires that an announcer, performer, etc. be sufficiently audible at a distance or over a large area.
Typical applications include sports stadiums, public transportation vehicles and facilities, and live or recorded music venues and events.
A PA system may include multiple microphones or other sound sources, a mixing console to combine and modify multiple sources, and multiple amplifiers and loudspeakers for louder volume or wider distribution.” (Wikipedia)
Components of a PA system
In addition to the microphone, amplifiers and monitors there are other components of a PA system, which include mixers, equalizers and faders.
Let us discuss each of these in detail
Mixers balance the sound of the instruments and microphones that are being amplified through the loud speakers.
You plug your instrument and microphone is their respective channel and from there you can control volume, equalization and amount of effect.
Equalization is the altering of a frequency response of an audio system using linear filters.
The majority of hifi equipment makes use of simple filters in adjusting bass and treble.
However, with graphic and paramedic equalizers, you can get a lot more flexibility in manipulating the frequency content of an audio signal.
Stereos and basic guitar amplifiers typically have adjustable equalizers which boost or cut bass or treble frequencies.
Mid- to high-priced guitar and bass amplifiers usually have more bands of frequency control, such as bass, mid-range and treble or bass, low-mid, high-mid, and treble.
Some amps have an additional knob for controlling very high frequencies.
Broadcast and recording studios use sophisticated equalizers capable of much more detailed adjustments, such as eliminating unwanted sounds or making certain instruments or voices more prominent.
Fading is the gradual increase or decrease in the level of an audio signal.
Fade in – is when a recorded song is gradually increased from silence in the beginning
Fade out – is when a recorded song is gradually reduced to silence at its end.
The usefulness of fading and cross fading is in ensuring that the beginning and the end of audio is smooth and without glitches.
Fade-ins and out can also be used to change the characteristics of a sound, for example a fade-in is used to soften the attack, especially in vocals where very plosive (‘b’, ‘d’, and ‘p’) sounds can occur.
It can also be used to soften up the attack of the drum and/or percussion instruments. A cross-fade can be manipulated through its rates and coefficients to create different styles of fading.
Faders are usually found in the channels of a mixer and are the button that slides up and down
Now I am going to take you through how to set up a PA system so that you can get the best out of your live performances.
First let’s talk about the type of microphone that you will be using.
The first piece of equipment that you will need will be a microphone
For live performances, I think the undisputed king for most musicians is the Shure sm 58
Next you will need some XLR cables that plug into your speaker or the mixer.
Powered speaker that you can connect an instrument or microphone into.
There are different set ups for PA systems. One of the simplest is a powered speaker that you can connect an instrument or microphone into.
This is especially good for those who may be playing the guitar and singing, as many of these will have 2 inputs.
There are even some options that come with EQ functions as well.
Powered speaker and a non-powered mixer
Another form of PA system set up is a powered speaker and a non-powered mixer. The mixer will have more effects and more EQ.
Plug the microphones or instruments into the mixer. Using XLR cables we will then connect the mixer to a powered speaker.
One of the benefits of this option is that because a powered mixer is relatively cheap, it becomes an easy way to enhance the functionality of your PA system.
Powered mixer and non-powered speakers
Then there is the combination of a powered mixer and non-powered speakers
Here the power is coming from the mixer. In this case you remove the speaker cables from the mixer and plug them straight into the speakers.
Non-powered speakers tend to be lighter due them not having any power. Because of not having to plug in the speakers, this option also means that there is less hassle to deal with.
Connect non-powered mixer and non powered speakers to a power amp.
Another option is to connect your non-powered mixer and your non powered speakers to a power amp.
Some would argue that this may not be a simple option but it is definitely worth considering.
Things to consider prior to setting up the PA system
There are a few things to consider prior to setting up the PA system
Turn down your master, volume channels and gain levels prior to turning on up your mixer.
When it comes to turning on your PA system, ensure that you turn down your master, volume channels and gain levels prior to turning on up your mixer.
If you do not, this can result in an awful level of feedback that can really turn the crowd off and potentially ruin your performance.
If you are using powered speakers ensure that the master level at the back of the speakers is down before you turn on your PA
Never point your microphone directly at the speakers.
This will produce feedback.
If in the unfortunate event that the you are performing at a gig and your speaker is behind the microphone and feedback is produced, make sure that you do not cover the microphone with your hand, it will only make things worse.
Always position your microphones in such a way as to ensure that your microphone and the speakers will never face one another.
Test the room for feedback.
Next it is important to test the room for feedback.
By minimizing the feedback through the EQ part of the mixer we can enhance the volume.
The best way to do this would be to try it out in a quiet setting.
What you want to do, is to turn up the main mix slowly until the point at which you hear feedback and then manage the feedback with your mixers EQ setting.
It would be better to get a mixer with a paramedic EQ , which can help you pinpoint the exact frequency and then bring down the feedback more accurately.
Turn the reverb down slightly
For those who love reverb, do realize that too much reverb can cause feedback.
I personally like to turn the reverb down slightly that way, I can get much clearer vocals.
In a performance, you ultimately want your vocals to be loud, as that’s what the crow wants to hear.
Other practical methods of enhancing your vocals are to ask your guitar player to turn down his amps slightly or ask the drummer to play a little softer.
These methods are not popular but they are practical for maximizing the performance.
Also try and add a little bit of kick drum to the PA system to enhance your performance and be more appealing to your audience.