Key takeaways

• What: Microphone gain is the amount of amplification supplied by the preamp it’s plugged into
• Why: Microphones are actually very quiet on their own, only producing extremely small voltages; they’re safe to use but need boosting, which is where the preamp comes in
• How: Plug your microphone into a mixer or audio interface. The gain knob should be near the preamp, usually marked with text or a clear dial. Turn up the gain gradually until the mic’s natural noise floor goes away and the sound you want is clear and well-defined. Listen out for unwanted background noise or distortion, if you notice these, pull the gain down until you can’t anymore

What is microphone gain?

Microphone gain is the amplification we add to a microphone via the preamplifier, or preamp. Because microphones have a pretty low output by default, they require a boost to their output to become audible. This is what preamps do, and they’re an absolute necessity for operating any kind of microphone in any context.

Fortunately, anyone recording or performing will have access to a preamp somewhere on either their audio interface or mixer. If you want to learn more about mic preamps, check out our guide to preamps.

When gain is set too low, you’ll hear the microphone’s natural noise floor very noticeably, and your intended signal will sound quiet, muffled, and distant. As you increase gain, the microphone’s self-noise – as it’s often referred to – will become much less noticeable, and the signal will become clearer.

However, if you push gain too high, you’ll notice a lot of background room noise, which will sound different to the microphone’s noise floor. Creaks in the floorboards, room echoes, and acoustic problems will become noticeable, and your main signal will distort in a nasty way. This can cause damage to the microphone capsule or clip the preamps in some way.

So, is gain just volume? In a sense, but there is a distinction in how and why they’re used. While they both deal with the loudness of signals, we can consider gain an input level control whereas volume controls a signal’s output level.

Gain also influences the tone and character of a sound; volume doesn’t. It’s even desirable sometimes, and somewhat commonplace, for studio engineers to push outboard preamps into distortion intentionally to get a unique effect. You’ll likely have heard this on vocals, guitars, and drum mics on some recordings.

Beware though, this trick won’t work on devices like audio interfaces or digital mixers and instead, results in an unpleasant digital distortion. Make sure you do this with analog preamps, analog mixers, or studio consoles if you want this effect.

We’ve taken a deeper look at the differences in our guide to gain vs. volume.

Getting set up

So, now that we’ve set out the basics of what gain is, we’re going to cover how to use it. First things first, you need to connect your microphone. Place your mic in a shockmount or clip on a stand, secure it in place, and get your stand to a comfortable position for whatever you’re using it on.

Run an XLR cable, the one with three holes on one side and three pins on the other, the holes in the cable will connect to the pins on the mic’s output. Then, run the pins on the cable to the input of your audio interface or mixer.

Finally, set phantom power if needed. If you’re not sure whether you need it, this is dictated by the type of microphone you’re using. Condensers require phantom power – unless they’re tube condensers, which come with their own external power supply. Dynamic mics don’t require phantom power, but won’t be harmed by it, although it’s still preferable to not activate it on them to keep every component in the mic safe.

Passive ribbon microphones can be damaged by phantom power in some cases, but active ribbon microphones will require phantom power. Make sure you know what you’ve got and that it’s not active until after you plug in your mic and you know it’s needed.

Phantom power will be readily available on most audio interfaces and mixers in the form of a switch or button, typically labelled “+48 V” as phantom power adds an extra 48 Volts of power to a microphone’s output.

How to set your microphone gain

Monitoring

First off, before you plug your microphone in, you’ll want to mute your monitors. If you switch on phantom power or plug your mic in with your monitors switched on, you’ll get a loud popping sound which can damage your ears and your speakers. Keep these muted until your mic’s plugged in and phantom power’s set, then unmute them and start listening.

As an additional tip, if you’re using a mixer or console, use the “PFL” (Pre-Fader Listening) or “Solo” button to isolate the mic you’re setting the gain of. This will ensure your channel monitors are showing you the levels of the mic you’re adjusting, and that your fader settings won’t impact what you’re hearing.

Make sure you have no additional processing on the channel as you set gain, no EQ or compression, as this will change the dynamics of your sound and give you an inaccurate impression of what you’re monitoring.

Soundcheck

To set microphone gain properly, you’ll need to get your signal going, so if you’re recording guitar, get your performer to start noodling while you set up the gain, or get a vocalist to sing. If you’re recording yourself, make sure you’re playing something too.

Think about the levels of what you’re playing, you don’t want to be caught out by sudden shifts in volume, so you or your performers should play some dynamic material. If you’re playing things with quiet and soft parts as well as loud parts, you should find it easy to find a sweet spot that covers both comfortably with minimal adjustment.

Be aware that performers tend to be more energetic during the start of a live set or recorded performance than while you’re setting up, so give yourself a little extra headroom for error – you can always tweak your gain settings if levels are consistent with your soundcheck once things get going.

Finding the right gain setting

As you turn up the gain gradually, listen very closely to your signal and think about what you’re hearing. The microphone’s natural noise floor will be noticeable if your gain is too low, and your signal won’t be very clear or sound muffled.

Gain and microphone sensitivity are very interactive, so the right levels of gain can bring up details in the signal – listen out for these and decide what feels right. As you get into the right zone of gain settings, you’ll notice certain parts of the sound pop out more.

The pick attack on the strings of a guitar, the breath in a vocalist’s voice, the scratch of a bow against violin strings, these can all be nice things to include, or they can be distracting.

You might like this detail or it might detract from the things you want to hear, it’s down to your preference, so listen closely and pay attention. If these elements become a problem, your gain might be too high. Your signal may distort, or you might notice a high level of room noise and ambience that becomes a detraction. All of these are signs that you’ve set gain too high.

The level meter

Level meters are found on most audio devices, some external preamps might not have one – although many do, but mixers, audio interfaces, and recording consoles always do. This may come in the form of a VU meter or an LED meter.

VU meters

VU meters are a classic form of monitoring seen in more vintage or vintage-inspired equipment.

Some older outboard preamps and recording consoles will have these things – a needle with a semi-circle labelled with values. If you’re using one of these, try not to let the needle hit the last third, which is usually labelled with a red colour. These meters are a little slower to respond than LED meters, so may not always be completely accurate.

LED meters

LED meters come in the form of coloured lights; they’re smaller and usually come with more modern or compact devices. You’ll see them on audio interfaces, mixers, and modern consoles. They’re faster, smaller, and usually more accurate, although sometimes they don’t give you a precise picture.

Most LED meters have multiple lights set up in vertical columns. The higher up the column the LEDs light up, the more gain your signal has.

LED meters are often – but not always – colour-coded for more convenience. Low gain settings will typically be green, mid-gain settings will be yellow, and high-gain settings will be red. The very top of the meter will be a clipping indicator. You want a gain setting where most of your signal sits in the green, but sometimes peaks into yellow. If you hit the red or the top of the meter, your signal is clipping.

High-pass and low-pass filters

Some sources have information you don’t necessarily need, and this can chew through your preamp’s headroom or simply make a signal sound unpleasant overall. This is where filtering comes in.

Midrange-focused instruments like guitars, vocals, and snare drums probably won’t need low-frequency information below 80 to 100 Hz, for example. This will conflict with bass guitars and kick drums, losing your clarity of low frequencies and getting your signal closer to clipping.

Engaging a high-pass filter – which is usually at a fixed frequency of 80, 100, or 120 Hz – can help give you some headroom back by cutting any signal below that threshold.

Low-pass filters are the same, but for cutting high-frequency information, making them great on bass guitars, kick drums, snare drums, and rhythm guitars in some cases. They will cut frequencies around 12 or 16 kHz, generally, removing treble that can be harsh or unnecessary on sources for more clarity and headroom. This can also give things like vocals, lead guitars, and keyboards more room to sit in the treble frequencies.

Most preamps, audio interfaces, and mixers will have at least a high-pass filter, but often have a high-pass and a low-pass filter. Some with switchable frequencies, some with fixed frequencies.

You can think of EQ in a similar way to filtering too, only more targeted and detailed. EQ is just another way of cutting out unwanted frequency information to let other instruments have a comfortable place in the mix and offering you more headroom in crowded frequencies.

Alternatively, EQ will let you boost frequencies you want to be heard, but be aware that boosts will use this headroom by adding gain to your chosen frequency on that channel.

What is clipping?

Clipping is a form of distortion that sounds broken and unpleasant. If your signal clips during recording, it’s difficult to salvage, even with audio repair tools. If a signal clips during a live set, it’s nasty temporarily, but the second you drop the gain of the offending mic, it won’t be a problem – just keep an ear and an eye out, watch your meters and listen.

Clipping refers to the audio waveform of a clipped signal, you can see it visually in recorded material, as the waveform itself will be squared off – meaning that the peak of the signal has effectively been lost, costing you detail and paying you back with a gift of a crackling distortion. It’s a part of all audio work – it just happens, but it’s worth preventing and responding to clipping whenever you catch it.

If you want to learn more, we have an in-depth guide to audio clipping. You might find out that clipping isn’t always the villain!

FAQs

What should I set my mic gain to?

You should set your mic gain to a level where your voice is clear and loud without causing distortion. This is typically around 50–75% but can vary based on your microphone and environment. Adjust gain slowly while monitoring levels to avoid clipping or excessive noise.

What happens if my mic gain is too high?

If your mic gain is too high, it causes distortion and clipping, leading to poor sound quality. High gain amplifies background noise, making audio harsh or unpleasant. It can also overdrive the signal, resulting in unnatural, overly loud recordings.

Can you damage a mic with too much gain?

Excessive mic gain cannot directly damage a microphone, but it can lead to distorted audio that’s unusable. Most modern microphones are built to withstand high levels of input, though consistently overloading your mic may strain your audio equipment over time.

Final thoughts

Gain is the core of audio engineering in all its forms. It’s integral to recording, mixing, and live sound, so it’s incredibly important to understand what it is and how to use it. Whether you’re recording yourself in a bedroom studio, working with a band in a project studio, running live sound for yourself or a live act, producing a radio show, or mixing sound at a large music festival – these principles remain the same.

Hopefully, this guide has given you a better understanding of what microphone gain is, why it’s so important, and how to control it to make your recordings and mixes sound that much better.

Want to learn more? With this overview being so general, you might want something more tailored to your use case. If you’re looking for ways to get an excellent sounding live mix, we have a comprehensive guide to live sound mixing.

Now that you understand gain, you might be looking for more technical information on microphones so check our guide to the different types of microphones you should know about.

And if you just want some extra hints to level up your mixing skills, check out our favourite mixing tips and tricks.