075 – Setting Gain
Correctly setting input gain is the first step to a great mix.
Written by Scott Adamson
It’s no exaggeration that gain is the most important knob on the mixing console. Simply put, your gain level will impact everything else that follows. Establishing solid gain structure is critical to achieving well-balanced mixes.
But what does “well-balanced” really mean in reference to mixes? Remember that boosting or cutting the gain turns that signal’s overall level up or down. When we mix multiple, often dozens, of audio signals together, we need them to be balanced in relation to each other. Establishing a healthy gain level is the best way to start.
Here’s a clip from our Live Sound Essentials course, where I run through my process:
When you plug something into the console, the first stop in the signal path is the mic preamp. A mic-level signal is very small, but the preamp is able to add a lot of gain to boost it up to line level. With either a mic-level or line-level input, you’ll be able to adjust the gain before the signal passes through the rest of the channel strip. At this point, if your various gain levels are balanced, everything else along the way will be easier.
So how do we actually set gain levels? There are multiple ways to approach this, but here is one tried and true method:
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You’ll use the solo/PFL button, the console’s meter, and a trusted pair of headphones. (They don’t have to be expensive, but it always helps if you’re familiar with how they sound.) Start with the fader turned all the way down and the mute button on. At this point, connect your mics and DIs. After that, hit your Solo/PFL button. PFL means “pre-fader listen,” which allows you to solo a channel even if the fader is pulled all the way down. Keep in mind that various console manufacturers use different terms for Solo or PFL. You may also see Cue.
By engaging the PFL button, you’ll first hear the sound in your headphones. This means you can make sure your signal sounds good before you put it through the main speakers. Once you have your gain at an appropriate level on your first channel, adjust your headphone output to a comfortable volume for listening. That way, as you move through the rest of your channels, the correct gain will actually sound like a sensible volume in the headphones.
In addition to hearing it, when you solo a channel, you'll also be able to see the signal level on a meter. Some larger consoles have meters for each individual channel, but most of the time you'll see the level of the solo’d channel on the main meter of the mixer.
Now we're ready to set the gain! The correct level will vary depending on the instrument and which dB scale your console uses. For most analog mixers or any board that utilizes the dBVU scale, you'll want to end up around 0 dB on the meter for inputs like guitar or keyboard and somewhere around +3 dB for drums. (Remember: 0 dBVU means you still have headroom!) If your console utilizes dBFS metering, the equivalent that guitar or keyboard channel would hover somewhere around ~18-20 dB.*
Once your gain is set, unsolo and unmute the channel. At this point, you’re ready to turn up the fader. Move slowly. If you reach halfway up the fader and it’s already way too loud, you’ll need to reconsider the gain structure. It might be necessary to lower the overall main LR mix or to change the input gain on the system processor. Or if you push the fader up to unity gain and it's much too quiet, then you also might need to change the gain somewhere else along the way.
Overall, if you set the gain level using the meter, turn the fader on the channel strip up to 0 dB, and also have the main output faders at 0 dB, then you should hopefully be getting a solid volume through the system. If all of this is set up properly, then we have a solid overall gain structure.
*Thanks to MT for the helpful reader feedback. It is crucial to remember dBVU vs. DBFS!
