Most PA systems, no matter how large or how small, are run in essentially the same way. Once the basic components of equalizer, soundboard, effects, microphones, amplifiers and speakers are in place, the basic principles for running a huge stadium PA are no different than those used for running a tiny coffee house system. This section will try to cover the basics of using all the major components of the PA, as well as getting all of them to work together as a whole to make the system operate at its best.

       After you have it all set up and connected, the first thing you will probably want to do is turn it all on. This is trickier than you might think. Although turning it on seems simple enough, doing it improperly can cause damage to some parts of the system. Specifically, in addition to scaring the heck out of the people hanging out in the room, the loud "pop" that sometimes occurs when you flip the "on" switch has the potential to tear up the midrange horns. Although there is no way to avoid this popping altogether, there are a couple of things you can do to keep it to a bare minimum.

       First, before you turn any knobs or switches into the "on" position, you should make sure that the master levels on the amplifiers and the soundboard are turned all the way down. If you don't make sure you check those levels, Murphy's Law might take effect and ensure that one of the levels is set incredibly high (maybe the slider got bumped in transit) which will cause horrendous and unexpected feedback immediately after flipping the "on" switch. That instant kind of feedback can easily blow a midrange horn. It's best to play it safe. The levels you should be most concerned with are the output levels on the amps (usually knobs), and the main outs (usually sliders) and monitor outs (sliders or knobs) on the soundboard. Once these levels have been "pulled down", it is safe to turn the system on. Other master levels such as those on the equilizers and effects are safe if left at or near their usual setting, but if you are in doubt (or haven't yet determined a "usual setting"), pull them down to zero as well.

       Secondly, the components of the system should be switched on in the following order:

[Effects, EQ] then [Mixer] then [Crossovers] then [Amps (lows first, highs last)]

       This order keeps the majority of the popping signals created by that initial power surge when each component is turned on from ever reaching the speakers. The main thing to remember is that the amps should be turned on last. The purpose of the amps is to increase the weaker line level signal to a high level signal that drives the speakers. If they aren't turned on, then there is no signal going out to the speakers. If the speakers don't get the high power signal from the amps, they can't "pop". Turning the amp on last reduces the number of "pops" from one for each piece of equipment you turn on to just one when the amp itself is switched on.

       Thirdly, whenever turning anything on (or off) that is connected to the PA system (microphones, keyboards, acoustic guitars...), make sure that the "mon" knob and the "level" slider for the channel it is plugged into is pulled all the way down. Switches on active mics in particular make loud pops when being turned on or off.

       Now that it is all turned on, the first thing to do is run the system through a series of tests to make sure everything is operating properly. There are a lot of things in a PA system to plug up, and it is very easy to make a mistake somewhere along the way. Running these simple tests will make it easier to quickly find and isolate these mistakes without any unnecessary aggravation. At first, it may look a little complicated, but once you get the hang of it you should be able to go through all the testing procedures in just a very few minutes.

       The least complicated system is of course the easiest system to test. To test the system pictured above, you need only go through a few simple steps. The steps listed below are there as a guide to help you locate any problems. Often there are many possible diagnoses to any particular difficulty, and I have only touched on a few of them. If something in your system doesn't work properly, and the suggestions listed don't seem to be the problem, you should first go back to "setting it up" and make sure you wired it all together properly. If it turns out that everything is hooked up correctly, you should then check all your cords to make sure they are working. After you have determined that they are in good shape, it is then time to look at the possibility that something may be wrong with one of the larger components of your system.

6. Turn the Main master slider or knob all the way back down. This will make it easier to hear your monitors independently of the mains while you make sure they are working correctly.
   
7. Gradually turn the master Mon (Volume or Level) knob or slider up to near its normal setting. On knobs, straight up at twelve o'clock is good. On Sliders, three quarters of the way up is good. Again, this isn't an exact science. Somewhere between one quarter and three quarters is fine.
   
8. Now, perform the same procedures described in step 3, step 4, and step 5, only this time make the adjustments to the "Mon" knobs or sliders rather than the main "Level" sliders or knobs.
   
   
   

       To test a stereo PA system, first follow steps 1 through 5 just like in the mono system, then procede to these next few steps.

1. While checking a microphone, gradually turn the main "Pan" knob all the way to the left. You should hear the sound gradually move entirely to the left main speaker (from the audience point of view) as you turn the knob. If not, check your connections to see if the "left speaker out" is connected to the left speaker and the "right speaker out" is connected to the right speaker.
   
2. Now, pan the sound with the main "Pan" knob all the way to the right. The sound should now move all the way to the speaker on the right side of the stage as it is viewed from the audience's perspective.
   
   

3. Finally, set the main "pan" knob back to twelve o'clock. Then check the "pan" knobs on the individual channels using the same technique. If the main "pan" knobs are working properly, and an individual channel's "pan" knob isn't, there may be an internal electronic problem with the soundboard.

       Once you have completed all of these steps with your powered mixer, and everything is working properly, you are finally ready to begin adjusting the sound of the system. You can skip the next several sections and go straight to "Signal Adjustment (Input/Output levels)".