10 Commandments For Better Digital DJing, #6

Last updated 10 April, 2018


PA #4
This commandment concerns the loud stuff…
Pic: All Pro Amps

There’s some stuff that all DJs – digital, CDJ, and vinyl – really do need to know. And one of those subjects is the topic of today’s Commandment for Better Digital DJing.

Without this knowledge, you’re never really going to be confident when you’re playing, and if something unfortunate happens while you’re DJing, you’re going to be in a poor position to do what’s needed to put it right. You’re going to make yourself look bad – and no DJ wants that. Let’s look a little deeper…

Today’s commandment

Today’s commandment is this:

Understand how a complete DJ PA system is set up, from mixer to speakers.

I explain in full detail just why this knowledge is so important, and give you an example or two of what can happen if you don’t make sure you know it (including one embarrassing event from my own past), in today’s video. In today’s resources, there’s a crash course on all this gear, plus tips and links to give you at least a fighting chance of being able to help when the inevitable happens and something goes wrong at one of your gigs.

As always for this special series, which is part of our Campaign for Better Digital DJing, we’re asking you to show your support and spread the word by clicking the Facebook Like button at the end of today’s post, if you enjoy it. Why? Because we want as many non-DJs and non-digital DJs as possible to be aware of the care and attention us digital DJs have in our craft, to hopefully raise the respect we get from the DJing and entertainment communities at large, and your “Like” will, in a small way, help us.





Club mixers
Mixers are basically big volume controls. They may all look different, but they’re really just like the mixer on your controller. The issue with using digital gear at bars and clubs is that you’ll probably have to get round the back of their mixer to plug yourself in, so always take a torch!

If you find yourself needing to set up by plugging into a mixer in a bar or club, either as the only DJ or when there are other DJs playing too, here’s what to do:

  1. Your input on the back of the mixer will have “line” or “CD” written by it – choose a spare one, and note its number (“line 1”, “CD 2” etc.). Be aware of the possibility of a tiny switch by your chosen channel with “line/phono” or “CD/record deck” or something similar – set this to line or CD, not phono or record deck
  2. Find the channel on the mixer that corresponds to where you’ve plugged in, and check it is switched to “line 1”, “CD 2” or whatever – often there’s a choice of what input is fed through each mixer channel
  3. Set the EQ on the channel you’ll be using on the bar/club mixer to flat (12 o clock), make sure the volume is up on your selected channel but it is not live (ie the crossfader isn’t allowing it to be heard), and start a track playing on your controller, making sure the controller or onscreen meters show it to be as loud as possible without clipping into the red
  4. Set the “cue” button to the channel you’re using on the main mixer, and you should now see the VU meter on the mixer indicating your signal is being received. You could plug your headphones into the main mixer temporarily rather than your DJ controller too, in order to check
  5. Adjust the mixer’s gain control to the point where the level is either the same as whatever is already playing through the mixer (say the previous DJ’s last CD), or – again – as high as possible without going into the red
  6. You’re ready to rock! Now when it’s time to start your set, you just move the crossfader across to your channel on the main mixer

Power amp

Amplifiers for bars and clubs are usually in mono, and instead of having left and right speaker volumes, they have zone or individual volumes for different speakers. Often there are separate amplifiers for bass and mid/treble speakers.

The big rule here is to not run them into the red, or at best, their automatic cutout will hit in, at worse you’ll blow the speakers. In either case, they’ll start sounding awful long before this happens. If you blow up a bar’s amp or speakers though being ignorant, they won’t thank you.

Amps can overheat, and if an air con unit is left off or fails in an amp room, for instance, it can cause issues – so if the amps are cutting out, look for air con malfunction, a broken internal fan or something similar.

I often chose to to walk around a venue, listening to every speaker before the start of my nights. If they are big cabinets, get down on your knees and check the bass, mid and trebles are working. If not, your night will sound worse, and it could just be that the amp isn’t turned up correctly, or it could be an issue – still, best to know.

Never turn equipment on or off with the amps turned on and their volumes up – turn amps on and off with their volume controls down, and do the same when connecting or disconnecting other gear. This stops the discordant bangs and pops of stuff powering up or down, and helps prevent speaker damage.

As I said in the video and above, be aware that most modern equipment (even your DJ software) has limiting built in to prevent you driving too far into the red, but you don’t want this stuff to kick in at all if you can help it, because it will make your music sound awful.

Always ask the venue if they have a house limiter of the type I spoke of in the video – the issue with these is that they can cut the sound completely if you play too loud, and it often won’t come on for a minute or so, and then get louder again gradually – it’s designed to p*ss you off, so don’t let it! Ask how loud you are allowed to go, and if you want to test it, do it early when nobody’s there. At least you’ll know for sure then how much leeway you’ve got.

Patch leads

Leads and cables
I gave you the bizarre story of the rolled-in extension cable in the video for today’s commandment. I guess that’s the kind of thing you only learn from experience, but you can teach yourself about the types of leads you’ll come across, and where they all work. Make sure you at least know and understand the uses for, and differences between:

  • Balanced XLR leads – with massive chunky plugs. Usually used to plug from mixers to amps, and amps to speakers
  • RCA leads – the red and white pairs. Usually used to plug individual pieces of DJing gear together, and into the mixer
  • TRS leads – these look like the big plug on your headphones. They can come in mono (one for a microphone, or a pair for mixers to amps / amps to speakers) or stereo (the one on your headphones)

It’s worth carrying spares of all the cables you might need.

Some useful links

We hope this material has been useful to you, and thank you once again for Liking this post in order to help us spread our campaign for better digital DJing far and wide…

• Watch out tomorrow for the seventh of our ten “commandments”. And thanks again for your support – it’s truly appreciated.

Check out the other parts of this series:

What are your views on our sixth commandment? Have you ever had to deal with a nightmare situation with a PA system or mixer at one of your gigs? Have you got any tips you’d like to share with us? Please let us know your thoughts and experiences in the comments.

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