Gain Structure for Church Sound: Where Should You Turn It Up?

Pros will tell you that gain structure is really important to making your mix sound its best. But what does that actually mean? And where should you turn things up and down on your soundboard?

There are several places that can change the level of the same signal. Choosing the right one makes your mix easier to control. Choosing the wrong one can throw off the band's in-ear mixes or leave you wondering why a channel still isn't coming through the mains.

Let's walk through what matters when you're running sound at church.

Gain structure starts before the soundboard

Here's the short version of the signal path: the source, the microphone or DI, the preamp, the channel processing, the channel fader, the master, and the system that feeds your speakers. Each stage affects what happens after it.

Our source is the first gain stage. If somebody sings quietly during soundcheck and then really projects during the service, we've set everything else around a level that has changed. Get the singer or musician playing at a realistic level before you start making decisions at the console.

Check the simple things, too. Does that condenser microphone or active DI need phantom power? Is a pad accidentally turned on and making the signal much quieter? Mute the channel before switching phantom power. Sometimes the fix is on the microphone or DI, before the signal ever reaches your gain knob.

Not every knob labeled “gain” does the same job

On the Allen & Heath SQ, you'll see gain controls in more than one place. They all change level, but they change different things.

• Preamp gain changes the analog input level before it becomes a digital signal. It affects everything fed by that preamp downstream.
• EQ gain boosts or cuts the frequency band you've selected.
• Compressor makeup gain changes the level after compression, before the channel fader.
• Digital trim changes the signal after analog-to-digital conversion. With shared preamps, it can let you adjust your console without changing the other console's preamp level.

Usually, when somebody says “turn up the gain,” they mean the preamp. But we need to be specific. Turning up one EQ band isn't the same thing as turning up the whole input.

Leave yourself some headroom

Headroom is the difference between your normal operating level and the point where the signal distorts. You want room for somebody to sing or play louder than expected.

Here's where the meters can get confusing: zero doesn't mean the same thing on every console. On a meter labeled in dBFS, zero is the ceiling. On the SQ shown in the video, the zero reference sits below that ceiling, leaving about 18 dB of headroom.

Know which scale you're looking at. Don't aim for a number you saw on the internet without checking what that number means on your console. If the signal clips during a live service, we don't get to fix everything in post. We've got to make it work right here, right now.

Get your faders into a useful range during soundcheck

When I'm teaching someone to run soundcheck, I like to have the band loop a chorus at full playing level. Then we bring up each channel and find a comfortable place for it in the mix.

My starting target is to get the channel faders between zero and negative 10. Zero is the nominal spot on the fader, not the bottom like the volume knob on your home stereo.

If the fader is way below negative 10 and that input is already plenty loud, you may need less preamp gain. If you're pushing above zero and still struggling to hear it, you may need more. Make those adjustments while you're setting up, and keep an eye on the meters.

There is an exception: if the input is already too low for the band's in-ear system but too loud in the room, turning down the preamp isn't going to solve both problems. We'll get to that in a minute.

Warn the band before changing the preamp

After soundcheck, leave the preamp alone until you can warn people. If somebody has that input turned up in their monitors and you add more gain, it gets louder for them, too.

Find an appropriate moment and give the band a heads-up: you're about to gain up the bass guitar, so it's going to get louder in their in-ears. Then they can adjust and accommodate it.

That one habit makes you a better team player. And if multiple consoles share the same preamps, remember that a preamp change can affect the broadcast console as well.

Digital trim and compressor output gain can be useful in particular situations, but they aren't a universal workaround. Know where your monitor feeds are taken from before deciding which control to move.

Meters moving, but no sound? Check your DCAs

A DCA is basically a remote control for the channel faders assigned to it. Imagine several TVs of the same brand responding to one remote. Their levels can move together while keeping the balance you already set.

Here's the trap: if the DCA is all the way down, pushing up an assigned channel fader won't bring that channel back into the main mix. You can have input signal, an unmuted channel, and audio in your pre-fader headphones, yet hear nothing from that channel in the mains.

Before you start setting gain and running soundcheck, double-check your DCAs and put them at zero. It's a simple check that can save you a lot of chasing around the console.

If the room is too loud, look downstream

Sometimes your channel faders are barely up and the room is already too loud. But turning down the preamps would leave the in-ear system without enough level. That's a sign to look farther down the signal path.

The system feeding your speakers may be set too hot for your normal operating level. Pulling down the master can get you through the moment, but it leaves the next sound tech a surprise when they put it back at zero.

Don't randomly turn every amplifier down the same number of clicks. If the system has been balanced, preserve that balance. An overall level adjustment in the system processor may be the right place. Another option is routing the main mix through a matrix and reducing the level there, so the master can stay at its normal position.

The goal is to give the console and the monitor system a healthy signal while keeping the room at an appropriate level. When the gain structure is working for you, the faders become tools for making musical changes.

See the controls on the console

Want to see exactly where these adjustments happen? Watch the full Gain Structure for Live Sound At Church video on YouTube. I'll walk you through the preamp, meters, channel processing, DCAs, and the output stages on the console.

Understand your sound system from source to speakers

If this is scratching that itch of “I really want to understand my sound system inside and out,” take a look at Attaway Audio Academy. The Amateur to Pro course walks through the sound system from the source to the speakers, with the details that help you make confident decisions at church.

And remember: nobody leaves church humming the kick drum.