How To Set Up A Simple PA System (Active & Passive)

 

In this blog post we will be demonstrating how to set up a simple PA system – whether you’ve set up a PA thousands of times, or never touched a mixing desk before, this guide will try to make setup as easy and painless as possible for everyone to understand.

First things first – you need to know if you’ve got an active system, or a passive system. There’s a big difference, as active speakers have their own amplifier inside, and passive speakers need to be powered by a power amplifier. An easy way to check which system you’ve got there is to check the back of your speakers – if they have a dedicated power socket, they’re most likely active speakers, if there’s just sockets for audio leads then they’re probably passive. See the images below for a more visual example of what you should be looking for:

Passive & Active Speaker
Active-PA-Setup

 

 

It’s most likely you’ll have an active system as they’re much more popular these days – there’s less to set up, transport, and generally just easier to use. So! In this example we’re gonna have the following equipment for a simple setup: (note – the items in this list are also links to categories on our main website so you can browse at your leisure!)

Just a quick explanation of why these things are included – The speakers are for amplifying the sound (obviously!), the mixing desk acts as your main control for everything involved – volume, EQ, pan, any effects, and much more!  The microphone is an example of how to plug in a live sound source, one XLR lead is for connecting the microphone to the mixer, and the other two are for connecting the mixer to the speakers Note that not all speakers / mixers use XLR leads, they can use jack leads, or a combination XLR – Jack lead, be sure to check which leads you need! Finally the 3.5mm Jack – RCA Lead is for connecting a music player, in this example it will be a mobile phone, but it can be anything with a standard earphone socket (sorry to all you iPhone users!).

Connect your mixing desk to your speakers using the XLR leads – to do this you’ll want to plug one lead into the left output of the mixer, and plug that into the speaker that’s on the left (stage right). As you probably guessed it’s exactly the same for the right output! You want to plug the lead into a ‘Line in’ if possible rather than a microphone input on the back of the speaker. This is because microphone inputs have a pre-amp in and will be expecting a much lower signal. Note – speaker placement is a suggestion; use your own judgement depending on where the desk is relative to the speakers. Just be wary of which way a channel will pan once set up!

 

Active-PA-System

Once your speakers are set up and connected to your mixing desk, it’s time to give it a try! To turn on a system, you want to turn on the mixing desk first, then the speakers. This alleviates any pops or unwanted sound escaping through the speakers that could potentially harm them. To pack back down you want to do this in reverse order, so turn the speakers off THEN the mixing desk off, this is once again to protect your speakers!

At this point we’re ready to test the system, but since both active and passive systems act the same way once set up, we will review how to get audio through your new set up PA System in one joint section.

 

Passive-PA-Setup

For a passive system there’s a couple of extra things to consider – most importantly is that the amp NEEDS to match the power rating of the speakers. It’s a little bit too in depth to go into in this guide, but keep an eye out for a future post encompassing all things power rating! Moving on though! For this system we will be using a very similar setup as the active system: (note – the items in this list are also links to categories on our main website so you can browse at your leisure!)

As you probably noticed, the power amplifier is different, and there’s a couple of new leads that weren’t present in the active system. The power amplifier is there to power the speakers, and the new leads are for connecting the mixer to the power amplifier, and the output of the power amplifier to the inputs of the speakers.

To begin – You’ll want to set up your mixing desk and power amplifier. You will be taking the MAIN OUT L&R of the mixing desk into their counterpart inputs on the power amplifier – in this example we’ve used XLR – Jack leads, but it’s dependent on your inputs and outputs! After you’ve done this, take the speakon leads and connect them from the output of the power amplifier to the input of each speaker – Once again,  speaker placement is a suggestion; use your own judgement depending on where the desk is relative to the speakers. Just be wary of which way a channel will pan once set up! Once this is all connected, you’re about ready to get some signal going through it!

Passive-PA-System

 

For a passive system you want to turn on the mixer first, then the power amp – to pack down it is reversed, so turn the power amp off, then the mixer. This is to prevent any damage to the amp and speakers, the same way it is with an active system.

 

Getting-Signal

With either system turned on and ready to go, you have to decide what you want your sound source to be – in this example we have both a microphone and an RCA lead for music. To make sure we’re getting audio through the system we will start with the microphone! To begin, find the master fader on the mixing desk (it’s generally on the right hand side, and is sometimes two sliders that work together, one controls the left output, the other controls the right – see the highlighted white section of the image below) and set them to 0dB, you can fine tune the loudness after we get some sound through the speakers but for now leave them set.

Grab your microphone, your XLR lead and plug the bottom of the microphone into any channel in the mixing desk (the lead will only go one way – female into the microphone, male into the desk. See the image below for an example of a channel input – it’s highlighted in red). Once you’ve done that, you’ll need to look for a ‘Gain’ pot. This is almost always directly next to where you’ve plugged in to, see the highlighted green area on the image below for reference. The gain controls how much signal is being sent to the channel it’s plugged into, but if you turn it too high you’ll be very likely to get a lot of feedback – this is an absolute no go in any live scenario – for reference it’s a very loud, high pitched squeal that will keep going until the offending channel has been turned down.

Alto Live 802

Alto Live 802

Optional Extra Knowledge –  This is often a good time to get familiar with the PFL function that some mixers have. PFL means ‘Pre Fader Listening’ and once selected it will allow the signal to go through the desk even with all of the faders set to the lowest setting, it doesn’t let any sound come through the speakers but it will visually show you via the meters on the desk how much signal is coming through the desk. Keeping the output signal in the green / yellow area is where you’ll get the best sound – anything in the red has a chance of being too loud and distorting, it doesn’t sound good, and isn’t good for your gear either, so be vigilant with your gain settings!

Once you’ve added some gain to the channel it’s the moment of truth! Slowly push up the fader for the channel your micophone is plugged into – which is highlighted in blue on the image above – whilst talking into the microphone (“Testing 1, 2! Testing 1, 2!”) and you should be able to slowly hear your voice be amplified through the speakers. Most of the other microphones/instruments you put through the mixing desk will follow these steps, so get used it! Take the time and practice setting up your PA system, as it can save valuable time and money when setting up for a gig.

Finally – to get music playing through your system, and really hear it properly – you’ll want to find where you can plug in an RCA cable into the desk, this is usually a small red and white socket next to each other with something like ‘Aux In’ wrote near it. If you look at the image below you can see these sockets are on the back of the Alto Live 802, highlighted in red.

Alto Live 802 Back

Alto Live 802 Back

Plug the red into the red, and white into white (it’s not going to break your system if these are the wrong way around, just the audio will be coming out of the opposite speaker). Sometimes the RCA input will be in line with a channel, and in that case, it’s usually the slide directly under it that will control the volume, but for mixers like the Alto Live 802 where the inputs are on the back of the mixer, there’s generally some volume control on the front of the desk (see the yellow highlighted area in the image of the front of the mixer above). Turn this up, and as long as your master fader is up (and the volume is up on the device you’re plugging in, it’s always worth a check to save headaches!)  you should be able to hear music coming through your PA!

Now pat yourself on the back for a job well done! It seems daunting at first, but as with anything, practice makes perfect! To see some of our best selling pre-configured PA Systems, click the first banner below, if you need any more help or advice, click the second and we’ll do everything in our power to get you the perfect system all set up!

 

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Posted on Wednesday, May 9th, 2018 in Blog

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