Setting up amps and speakers

Introduction

An Amp or "amplifier" is what the name says - takes a signal, makes it big (amplifies) to drive some speakers. In our case it takes an audio signal from our console or source to make it loud enough to listen through the speakers  An example is like the little box you see under your tv or computer running your 5.1 surround sound speakers etc - except ours is bigger :-)

Speakers

There are two most common types of speakers - powered and unpowered. Unpowered speakers rely on an external amp to drive the speaker, while a powered speaker has the amp built into the cabinet. You can usually tell which one you have if you look at the back of your speaker - if it has a power plug, volume dial in addition to the ins/outs, can take direct XLR or jack/phono - then it’s a powered speaker. Likewise unpowered speakers only have just ins/outs on the back, and its either a jack, XLR, Neutrik connectors (common) or simply just two wound terminals to attach your +ve/-ve cable from the amp to (not so common for audio production use, but exists on a lot of consumer/home systems).

Amplifiers

There are many types of amplifiers with different power ratings, channels, classes and quality. You can look up the information on google, I will add to this section later when I have time.… PLACEHOLDERLINK

Connecting the speakers and amps

Connection is quite simple to do: connect everything, power on last.

1. Make sure amp/speaker is turned off
2. Connect the output of your console or audio source to the amp’s input (usually XLR).
3. (unpowered speakers + amp combos) Connect the speaker line out from the amp to the speaker inputs
4. Connect any other additional speakers or devices if needed.
5. Connect the power cable to the amp or powered speaker

Turning on the system

Yes that’s right. The power up procedure needs its own subheading because it’s just that important. Making sure you power on in the correct manner makes sure you don’t accidentally blow up anything or destroy anyone’s ears.

1. Make sure amp/speakers are OFF. Set amp volume knob to “OFF” position or full minimum volume
2. Turn mixing desk and any other sources on FIRST
3. Make sure there is no audio signals being sent through the output of the desk (i.e. FOH/mains faders OFF)
4. Turn amp/speakers on

Calibrating/prepping the amps and speakers

Before you use an amp or powered speaker for the first time in a venue or gig, you would need to calibrate it. It's much like turning up the gain on a mic/instrument so you can get a decent level into the desk, but this time you're going to be feeding an amplified signal to the speakers.

 

Please be careful when you’re setting up the levels to the speakers (especially unpowered ones). Some speakers won’t be able to take too much power so if it is too high you may blow them. Likewise some amp's volume dial is VERY SENSITIVE. Bring it up slowly until the right level is achieved.

1. Use an existing sound source (either a mic plugged in that is soundchecked properly) or a mp3/computer playing back a song
2. Bring the source volume to required levels on the desk’s level meters (i.e. turn up the faders till you get a decent signal from the meter, or to a known level that works well)
3. Bring up the FOH/Mains faders up to Unity gain SLOWLY
4. Turn up the volume knob of the Channel A of the amp until desired level is reached.
5. Do the same for Channel B and any other channels you use.
6. For any foldback monitors you will need to raise the volume up SLOWLY to the desired level, and then adjust it again when the band member comes for soundcheck
7. You may need to change the Graphic EQ, compressor, limiter and some other settings to adapt to your room’s sound.

 

Glossary:

Unity Gain = Optimum level on the desk for sound/signal to go through. Usually marked with a “U” and/or a thick black line on the fader/pot.