Setting Up A PA System
The above example is about as basic a system as you can get. Hooking it together is relatively simple. The most important thing to remember when hooking up any size PA is the direction of the signal. This is indicated above by the red arrows. The signal starts with your mouth (or drum, or horn, or whatever), then goes through the microphone into the system, then routes its way through the amp, and finally into the speaker where it leaves the system as a much louder sound. A good rule of thumb is to remember that when plugging something in (like an amp), whatever you plug into the input should be coming from the direction of your mouth while whatever you plug into the output should be heading toward the speaker.
With the addition of a mixer (soundboard), an equalizer (EQ), and a set of full range speaker cabinets, we have created a small PA system that can be used both for rehearsal and for some gigs. The principle of signal direction stays consistent. As the arrows indicate, the signal again starts at the microphone passing through each component in turn until it reaches the speakers where it exits the system as an audible, much louder sound. It is important to note the order in which the components are hooked up. No matter how many more components (such as effects or compressors) are added, these basic building blocks should always line up in this order relative to each other. The EQ should always be connected somewhere between the output of the mixer and the input of the power amp, the microphone should always be on the input side of the mixer, and the speakers should always follow the amplifier.
PA Systems come in many different shapes and sizes,
ranging from the very elaborate systems used in large stadiums all the
way down to a simple microphone patched into your home stereo. Listed
below are several of the most common setups.
The Bare Bones
The above example is about as basic a system as you can get. Hooking it together is relatively simple. The most important thing to remember when hooking up any size PA is the direction of the signal. This is indicated above by the red arrows. The signal starts with your mouth (or drum, or horn, or whatever), then goes through the microphone into the system, then routes its way through the amp, and finally into the speaker where it leaves the system as a much louder sound. A good rule of thumb is to remember that when plugging something in (like an amp), whatever you plug into the input should be coming from the direction of your mouth while whatever you plug into the output should be heading toward the speaker.
An easier way to think of it might be to think of
it as a river, the microphone being upstream, the speaker being
downstream, and the amp being a reservoir in between. As the water (the
signal) flows from upstream (the Microphone), it must enter the
reservoir (the amp) through an input, and then exit the reservoir through an output until finally, it reaches the downstream side (the speaker).
So, that's the theory (complete with a
picturesque metaphor). Now here is the reality. In the example above,
you would plug things up in this order.
-
Plug the mic cord into microphone (There is only one place to plug it in. Technically it's an "output").
-
Plug the other end of the mic cord into the "input" of the amplifier (remember, input is coming from the microphone).
-
Plug the speaker cord into the speaker "output" of the amplifier (the signal is flowing out of the amp toward the speaker).
-
Plug the other end of the speaker cord into the "input" on the speaker (the signal is coming from the microphone through the amp to the speaker).
And there you have it. You have successfully
hooked up your first basic PA system. Of course, although it will
amplify the sound, this particular system won't be of much practical use
to you in any real life playing situation. It still lacks three
essential ingredients.
The Essentials
With the addition of a mixer (soundboard), an equalizer (EQ), and a set of full range speaker cabinets, we have created a small PA system that can be used both for rehearsal and for some gigs. The principle of signal direction stays consistent. As the arrows indicate, the signal again starts at the microphone passing through each component in turn until it reaches the speakers where it exits the system as an audible, much louder sound. It is important to note the order in which the components are hooked up. No matter how many more components (such as effects or compressors) are added, these basic building blocks should always line up in this order relative to each other. The EQ should always be connected somewhere between the output of the mixer and the input of the power amp, the microphone should always be on the input side of the mixer, and the speakers should always follow the amplifier.
Keeping in mind signal direction, the system shown in example 2 should be hooked up like this:
-
Plug the mic cord into the microphone (only one end of the cord will fit).
-
Plug the other end of the mic cord into any "input" channel of the mixer (input comes from the microphone).
-
Plug a high Z cable (patch cable) into the "main out" of the mixer (the signal is flowing out of the board toward the speakers).
-
Plug the other end of this cord into the "input" of the equalizer (the signal is flowing from the microphone).
-
Plug one end of a high Z cord into the "output" of the equalizer (the signal is flowing out of the EQ toward the speakers).
-
Plug the other end of this cord into the "input" of the power amp (the signal is flowing from the microphone).
-
Plug two speaker cords into two speaker "outputs" on the power amp (the signal is flowing through the amp toward the speakers).
-
Plug the other ends of these cords into the "inputs" of the speakers (the signal is coming from the microphone to the speaker).
Warning:
Never plug anything other than a speaker into the output of a power amp. A "speaker out" connection carries a very strong signal that can and probably will cause damage to the other components. |
