A lot of DJs use expensive sound systems regularly, but without proper knowledge of how to set the gain stages on each piece of gear, you run the risk of damaging your system. Today, guest contributor DJ Soo has written up the basic idea behind why gain staging matters, how to do it on a typical setup, and why staying out of the red is so important on a properly staged rig.
What Is A Gain Stage?
Let’s start of this article by discussing what exactly gain stages are and why they matter in a DJ setup. First up, what is gain itself? It’s the electronic process of amplifying your signal (making it louder!). You have control over the gain at gain stages – points in your audio chain where you can change the level of volume of your sound. The majority of DJ mixers have three gain stages:
- the input gain (gain/trim knobs)
- the channel output gain (your volume faders)
- the output gain (your master volume knob/fader).
After this, you will have your amplifier gain which is either your amplifier volume, or in the case of powered gear, the volume knobs on the speakers themselves. In a digital software setup, there is also two more gain stages within the software – individual track gains and a master volume gain.
Some setups will have your mixer/controller plugged into another mixer which will add additional gain stages to your setup.
How Does Gain Staging Affect Sound Quality?
Not to get into the physics of everything, but each of the gain stages have a maximum value – going beyond that will result in clipping which is something you want to avoid. The distance between your signal and the max amplitude of the stage is called headroom – run out of headroom, and it clips! Clipping leads to distortion and in the best case scenario, will make your music sound bad and in the worst case scenario, can damage your speakers.
Remember that if you clip anywhere in your stage, it can still cause distortion even if the signal after your clipping point isn’t clipping. Basically all you’re doing is amplifying a clipped signal and making still putting out a distorted sound.
The optimum level for your gear is often marked as 0 db on your equipment.
Staying Out Of The Reds
Gain structure is a big reason that sound techs absolutely hate it when DJs play into the red. Any professional system will be gain-staged during setup to have the ideal sound quality when the DJ mixer is hitting right before the reds. Because most of these systems have the DJ mixer sending to a mixing board, the sound guy will still have control over the master volume and all hitting reds will do is make everything sound worse.
How To Set Your Gain Stage
So how do you set your gain stage? It’s rather simple – you want to go down the chain of audio devices and find the maximum level for each of the stages before clipping and essentially leave them there. Ideally, you want your music to average out around the 0db mark (top green) with certain peaks hitting into the oranges.
- Start with your DJ software. Either set the track gains manually one by one, or use the auto-gain setting in your software so that your tracks are generally hitting just below the reds.
- Repeat the process for master software output, although leaving it at 12 is usually your best bet.
- On your mixer/controller, start with the input gain – set the gains in the channel to peak just before hitting reds, while having your channel fader all the way up. This will be the highest gain you want to go on each channel.
- Do the same with the mixer’s Master volume. Watch master output lights, and make note of where the Master knob is.
- On the speakers’ amplifier, do the exact same thing, turning it up until you see the levels hit just before the reds. If you’re using powered gear, turn it up until you see the limit light on your speakers just start to blink and then ease it back. If you’re using tops and subs, balance out the signal between the two at high volumes until you think the highs and lows sound good – I would start with the subs, since subs tend to limit a little faster than tops. In some systems, you can see the limit light blink a bit and still be ok – just don’t get to a point where the light is constantly on.
- Remember to either use your sub crossover if it has it (send the cables through the subs to your tops) or turn on the high-pass on your tops if it has one. Passive gear will require an external crossover.
Leave Yourself Headroom
Once the system is sounding good, turn down one of the master controls (we recommend the master on your mixer/controller) and use that to control the overall volume of your setup as needed. You should notice where the maximum point is on that knob and never go above it – some sound techs will actually put a marker at this point to indicate where it should never exceed.
Remember to keep your channel faders out of the reds!
You have now found the loudest point your system can handle. Chances are it will be way louder than you need so you won’t have to worry too much about even approaching that point. If you have reached the maximum point and it’s still not loud enough, that means you need more sound or need to upgrade your sound system.
The amount of volume you need throughout the night will change! When the room fills up, people’s bodies absorb a lot of sound. Be ready to adjust your master – this is why having good amount of headroom is important.
We realize that this is the ideal way to sound check and find the limits of a DJ sound system, but in practice, some venues don’t want you blasting out sound during sound check so maybe for the last stage, you don’t have to find the absolute limits of the speakers. But having a good idea of how much sound is available is important so you don’t end up cranking up the wrong gain late in the night and distorting everything!
Have questions about setting gain stages? Let us know in the comments.