Gain vs. Volume: What Production Sound Mixers Need to Know

Gain and volume are two of the most commonly confused concepts in audio. Both can make something seem louder or quieter, but they control different parts of the signal path and serve different purposes.

For a production sound mixer, understanding the difference is especially important because incorrect gain can damage the quality of a recording, while changing the volume usually affects how loudly that already-established signal is being monitored or mixed.

A simple way to think about it is:

Gain controls the signal coming into the system.

Volume controls how much of that signal is being sent out or added to a mix.

They are related, but they are not the same thing.

Where Gain and Volume Sit in the Signal Flow

Going back to our signal-flow road analogy, gain and volume are located at different places along the road.

A simplified signal path might look like this:

Microphone → Preamp / Gain → Recorded Track → Mixer / Fader → Output → Headphones

Gain appears near the beginning of the road. It determines how much the weak microphone signal is amplified as it enters the mixer/recorder.

Volume controls appear farther down the road. They determine how much of that signal is sent into a mix or how loudly that mix is sent to an output such as headphones.

This difference in location is one of the easiest ways to understand why gain and volume behave differently.

What Is Gain?

A microphone produces a relatively weak electrical signal known as a mic-level signal. Before that signal can be properly recorded and processed, it usually needs to be amplified. Inside the microphone input of a mixer/recorder is a preamplifier, or preamp, that increases the strength of that incoming signal.

The gain control determines how much amplification the preamp applies. If the microphone signal is too weak, increasing the gain makes it stronger. If the signal is already strong, less gain may be necessary.

This process of setting the incoming signal to an appropriate level is known as gain staging.

Gain Happens Early in the Road

Gain affects the signal before it reaches many of the other parts of the recorder.

Imagine an actor speaking into a shotgun microphone. The signal might travel like this:

Actor → Microphone → XLR Cable → Preamp / Gain → Recorder

The microphone creates the electrical signal, and the preamp determines how strongly that signal enters the recording system.

This means that problems created at the gain stage can continue farther down the road.

What Happens When Gain Is Too Low?

If the gain is set too low, the recorded signal may be unnecessarily quiet.

You may be tempted to increase the signal significantly later during editing. Doing this can also make background noise and other unwanted components of the recording more noticeable.

A very low recording level can also make it harder to judge what is happening while monitoring on set.

The goal is therefore not simply to avoid clipping. You want the desired sound to enter the recorder at a healthy level while still leaving enough room for unexpectedly loud moments.

What Happens When Gain Is Too High?

If the gain is too high, the signal can overload part of the recording system. You may hear the microphone described as being too hot.

As the signal approaches the maximum level the system can handle, it can distort. If the signal exceeds that limit, it may clip.

Clipping happens when the system can no longer accurately represent the top of the audio waveform. Instead of continuing naturally, the waveform is cut off or flattened.

Once clipping has been recorded into a conventional audio signal, lowering the volume afterward does not restore the missing information.

That is why proper gain staging is so important.

Leave Room for Louder Moments

People do not speak at exactly the same level all the time. An actor may be speaking quietly during rehearsal and suddenly yell during the actual take.

If you set your gain so high that normal dialogue is already approaching the maximum recording level, there will be very little room available when that actor becomes louder.

The difference between the normal operating level and the maximum level the system can handle is often called headroom.

Leaving sufficient headroom gives the signal somewhere to go when the source suddenly becomes louder.

For production dialogue, you generally do not want normal speech constantly approaching 0 dBFS. You want a healthy signal with enough space above it to accommodate louder words, laughs, shouts, or unexpected changes in performance.

Watching Your Meters

The meters on your mixer/recorder help you determine how strong the incoming signal is.

Digital recorders generally measure recording levels in dBFS, or decibels relative to full scale. dBFS is the measurement used to represent audio level in a digital system, where 0 dBFS is full scale (the maximum possible digital audio level) and lower levels are measured using negative numbers.

On this scale:

• 0 dBFS is the maximum digital level
• Everything below it is represented with negative numbers
• That means -12 dBFS is louder than -24 dBFS

For normal production dialogue, you will often see levels moving somewhere around the -20 to -12 dBFS range, with louder peaks going above that while still remaining safely below 0 dBFS.

The exact level will depend on the performance, microphone, recorder, workflow, and amount of headroom you want to maintain.

Meters are an important guide, but they should always be used together with your ears.

What Is Volume?

Volume controls how loudly an existing signal is being reproduced, monitored, or included in a mix.

Unlike input gain, changing your headphone volume does not change the microphone signal that was originally captured.

If your recording is properly gain staged but sounds too quiet in your headphones, you can simply increase the headphone volume. The audio file does not suddenly become louder. You are only changing how loudly you hear it.

The road might look like this:

Recorded Signal → Headphone Output → Headphones

The headphone volume controls the level at the end of that road. It does not go back to the beginning and change the microphone's input gain.

Gain vs. Headphone Volume

This distinction is extremely important when monitoring.

Imagine your headphones are too quiet. You could increase the microphone gain, and the headphones would probably become louder. But you would also be changing the recording level. That is not the correct solution if the microphone signal is already at a healthy level.

Instead, increase the headphone volume. The microphone gain determines the level being captured. The headphone volume determines how loudly you hear that captured signal.

These are two separate controls serving two separate purposes.

Volume Within a Mix

The word volume can also refer to how much of a particular track is included in a production mix.

Most mixer/recorders provide faders or channel controls that allow you to raise and lower individual sources within the mix.

Imagine you are recording three microphones:

• Boom
• Actor 1 Lav
• Actor 2 Lav

Each microphone can have its own properly adjusted input gain.

Boom → Input 1 (55 Gain) → ISO 1

Actor 1 Lav → Input 2 (20 Gain) → ISO 2

Actor 2 Lav → Input 3 (25 Gain) → ISO 3

You can then decide how much of each microphone you want to include in the production mix.

Boom → Input 1 (55 Gain) → ISO 1 → Input 1 Fader (0) → Production Mix

Actor 1 Lav → Input 2 (20 Gain) → ISO 2 → Input 2 Fader (0) → Production Mix

Actor 2 Lav → Input 3 (25 Gain) → ISO 3 → Input 3 Fader (0) → Production Mix

If Actor 1 is naturally much louder than Actor 2, you could lower Actor 1's fader and raise Actor 2's fader to create a more balanced mix.

Actor 1 Lav → Input 2 (20 Gain) → ISO 2 → Input 2 Fader (-5) → Production Mix

Actor 2 Lav → Input 3 (25 Gain) → ISO 3 → Input 3 Fader (+10) → Production Mix

If Actor 1 Lav and Actor 2 Lav sound better than the Boom, you can lower the Boom's fader until it is no longer present in the production mix.

Boom → Input 1 (55 Gain) → ISO 1 → Input 1 Fader (-60) → Production Mix

Those fader adjustments do not change the isolated (ISO) recordings of those microphones. The recorder can continue capturing the original ISO tracks while you independently adjust how much of each track appears in the production mix.

Gain Changes the Input, Faders Change the Mix

This gives us another useful distinction: gain determines the level entering a channel, and the fader determines how much of that channel is added to the mix.

Imagine a microphone has been correctly gain staged. Its isolated recording sounds good. But you decide that microphone should not appear in the production mix at all, like in the previous example. You can turn its fader all the way down.

The microphone can still continue recording to its isolated track even though it is no longer being added to the mix, depending on how your recorder is configured.

This is why production mixer/recorders separate input gain from mixing controls. They perform different jobs.

A Water Analogy

Another way to understand gain and volume is to imagine water traveling from a valve through a garden hose to a trigger spray nozzle.

Gain is like the valve at the beginning of the hose. Opening the valve determines how much pressure and potential flow are being supplied to the system.

Volume is like the trigger on the spray nozzle at the end of the hose. Pulling the trigger determines how much water is allowed to come out. Pull it slightly and only a little water comes out. Pull it fully and much more water comes out.

The important distinction is where each control acts. The valve controls the water entering the system near the beginning, while the trigger controls what comes out at the end. In the same way, gain controls the audio signal near the beginning of the signal path, while volume controls how much of that established signal is sent to an output or mix.

Follow the Road When Troubleshooting

Signal flow can help you determine whether you should adjust gain or volume.

Imagine you cannot hear your microphone very well. Start following the road.

Microphone → Recorder Input → Gain → Track → Headphone Output → Headphones

First, look at the input meter. If the meter barely moves when the actor speaks, the incoming signal may be too low. You may need to examine the microphone position, microphone output, wireless settings, input type, or gain.

But if the meter shows a healthy signal and you simply cannot hear it loudly enough in your headphones, the input is probably not the problem. Move farther down the road. Check your headphone routing and headphone volume.

The meters tell you that the signal successfully reached the recorder. Your job is now to find out why you are not hearing it properly farther down the signal path.

Don't Use Gain as a Volume Control

One of the most important habits a beginner can develop is resisting the temptation to use gain whenever something sounds too quiet.

Ask yourself: is the signal itself too low, or do I simply want to hear it louder?

If the recorded signal is too low, investigate the gain stage. If the recorded signal is healthy but your headphones are too quiet, raise the headphone volume. If the microphone is properly recorded but too quiet compared with other microphones in your production mix, adjust its fader.

These controls may all make something seem louder, but they are changing different parts of the signal path.

Microphone Placement Comes Before Gain

Before reaching for the gain control, also consider where the microphone is positioned.

If the microphone is too far away from the actor, increasing the gain does not magically make the microphone closer. It amplifies everything the microphone is capturing. That includes the actor, but it may also include room ambience, air conditioning, traffic, reflections, and other unwanted sounds.

Moving the microphone physically closer to the desired source usually improves the relationship between the wanted sound and the unwanted background sound.

A good recording therefore begins with proper microphone placement. Gain is used to properly amplify that signal after you have captured the best sound you reasonably can at the microphone.

Gain Staging Across Multiple Devices

The idea of gain becomes even more important when several devices are connected together.

A wireless microphone system might have a signal path like this:

Lavalier Microphone → Transmitter → Receiver → Mixer/Recorder

Several stages in that road may have their own level controls. The transmitter may control the level entering the wireless system. The receiver may control its output level. The mixer/recorder then has its own input settings.

If one stage is set incorrectly, changing another stage may hide the symptom without solving the actual problem. For example, an overloaded transmitter may already be distorting before the signal ever reaches your mixer/recorder. Lowering the recorder's gain will make the distorted signal quieter, but it will still be distorted.

This is why proper gain staging means looking at the entire signal path, not just the gain knob on the recorder.

Gain, Volume, and Signal Flow

Using our road analogy, we can now see how these controls fit into the larger system.

The signal begins at the microphone:

Actor → Microphone

It travels into the mixer/recorder:

Microphone → Preamp / Gain

The recorder captures that signal:

Gain → Recorded Track

The signal can then travel down several different roads:

Recorded Track → Production Mix

Recorded Track → Headphones

Production Mix → Camera

Production Mix → IFB

Gain is located toward the beginning of the road. Volume and mix controls generally operate farther down the road. Knowing which section of the road you are adjusting makes it much easier to choose the correct control.

Conclusion

Gain and volume can both make audio seem louder or quieter, but they perform very different jobs.

Gain controls the strength of the signal entering the recording system. Volume controls how loudly an existing signal is monitored, reproduced, or included in a mix.

If your microphone signal is too low or too high at the input, adjust the gain. If the recorded signal is healthy but your headphones are too quiet, adjust your headphone volume. If one microphone is too loud or quiet compared with another in your production mix, adjust the channel's fader.

The easiest way to determine which control you need is to follow the signal flow and ask where the problem is occurring. Once you understand where gain and volume sit along that road, the difference between them becomes much easier to understand.