If you’re new to audio production, you may have come across the term “gain staging”.
Gain staging is the process of setting the level of the audio signal at each stage of the signal path. It might not be the most exciting topic, but it’s a crucial engineering technicality to conquer if you want crystal-clear recordings.
With gain staging, you’re optimizing the levels in your signal path, while making sure that each processor is working optimally and not clipping the signal.
Read on to learn how to do proper gain staging. Let’s kick things off!
What Is Gain?
Before we take a deep dive into the world of gain staging, we should take a step back and discuss some audio engineering basics.
Let’s start with gain!
Gain is the strength or level of an audio signal. It is typically measured in decibels (dB). A higher dB means a stronger signal.
It’s usually applied to the input stage of an amplifier, boosting the incoming signal so it can be amplified to a higher level.
Let’s take an example:
Microphones record at what is called mic-level. This signal is usually around 1-5 millivolts (mV) and to make it useful you’d need to boost it to a line level of 600-1,000 millivolts (mV).
This is where gain kicks in!
Gain is the amount of amplification that’s applied to your microphone signal before any additional processing. It’s measured in decibels (dB), and it can be adjusted on your audio interface, mixer, or preamp. As previously mentioned – the higher the mic gain, the louder the signal will be.
So what about volume?
Volume is how loud the signal is after the processing. It’s measured in decibels as well, and it can be adjusted on most audio interfaces, mixers, and music production software.
You also need to understand the concept of signal chains!
A signal chain is a route an electric audio signal takes from its source to its destination.
The term can refer to either the physical pathway of cables the signal travels through or the order in which the signal passes through various software devices that modify or process it.
The concept of gain staging refers to setting the level of each individual component in the signal chain so that the overall system has enough headroom to avoid clipping and distortion.
Example of a basic signal chain:
- Audio Interface (input)
- DAW Channel
- DAW Mix Bus
- Audio Interface (Output)
You see, setting the levels of each component above is crucial to getting good sound quality. If any one stage in the chain has too much gain, it can introduce noise and distortion into the signal.
Understanding Gain Staging
We got the basics covered. So what about “gain staging”?
Gain staging is the process of setting the level of each individual stage in an audio signal chain so that the overall signal level is optimized.
The goal of gain staging is to minimize noise and distortion while maximizing headroom, which is the amount of signal that can be processed before clipping occurs.
There are a few different ways to set up gain staging, but the most important thing is to make sure that each stage in the chain is operating at its optimal level.
By doing this, you’ll get the cleanest, most powerful sound possible.
To break it down even further, gain staging is all about balancing between two main things:
- Noise floor
The noise floor is the background noise present in all audio recordings. It is typically a low, hissing sound that is barely audible (hopefully).
This inherent noise can be generated by many factors:
- Electrical interference
- Tape hiss
- Mechanical vibrations
- Thermal noise
- The device itself (self-noise)
- Microphone cables
- Audio interfaces
The noise floor can have a significant impact on the quality of audio recordings.
If the noise floor is too high, it can dim delicate sounds and make it difficult to hear quiet passages.
This is why you must keep your noise floor as low as possible.
Well, there are several techniques including EQing, gating, and noise reduction.
By understanding the causes of noise floor and how to reduce it, you can ensure that your audio recordings are as clean and clear as possible.
Headroom is the amount of space between a signal’s peak amplitude and the point at which distortion begins.
Think of it as the safety zone that gives audio engineers the ability to apply processing to a signal without pushing it into the red and causing clipping.
It’s important because it allows for transients in the signal to be reproduced without distortion.
Transients are those brief, sharp peaks in the waveform that occurs during the initial hit of a sound.
These peaks will be clipped if there is not enough headroom, resulting in distortion.
It’s when you run out of headroom that distortion occurs.
The signal-to-noise ratio (SNR) is a measure of the performance of an audio signal. In other words, the amount of strong and clean signal present in relation to the level of background noise.
It’s calculated by comparing the strength of the audio signal to the base level of noise in the system.
As an example:
A high signal-to-noise ratio means that you have a loud signal compared to the noise floor. Simply put, great sound quality!
How Gain Staging Improves Your Tracks
If you aren’t sold yet:
Gain staging helps to minimize noise and distortion in your tracks.
As a result, you’ll have a high signal-to-noise ratio and your tracks will sound clear, polished, and more professional.
You see, every VST plugin you load inside your DAW is part of the signal chain and alters the gain to some degree.
Consequently, it also affects how the next gear in the chain processes the sound.
Whether you’re using analog or digital gear (or a combination), it’s all about making the most out of your processors in your signal chain by feeding them with optimal levels.
How To Gain Stage When Recording
Record At Optimal Levels
Setting proper gain levels in your preamp is one of the most important aspects of getting a good recording.
If the gain is too low, the recording will be noisy and lack clarity.
On the other hand, if the gain is too high and the needle is consistently hitting the red, you’re probably clipping and that will result in distortion.
It is important to record at optimal levels to avoid clipping and achieve the best possible signal-to-noise ratio.
Thus, when recording, it is important to keep an eye on the meters in your DAW and make sure the levels are set correctly.
So what is the optimal level?
Your meters should hover at around -18 dBFS while peaking at -10dBFS.
This will leave enough headroom for the signal to be amplified without clipping or distortion. You would need to decrease your gain if you start peaking at around -6dBFS.
Besides, recording at around -18 dBFS will give you a loud enough signal that won’t be drowned in the inherent noise floor.
So, always keep an eye on your meters in your DAW. They have numbers next to them, showing you how loud the channel is in dBFS.
Furthermore, one of the most common mistakes I see is producers recording their instruments too loudly, hoping to get a “beefier” sound.
It may sound counterintuitive, but if your recordings are too loud, your song will sound quieter.
You won’t be able to turn up the levels to match pro standards. You see, most of the “loudness” is achieved in the mixing and mastering process.
If you don’t leave enough headroom in the recording phase, there is no room for the mastering engineer to work with. You will be stuck with a song that sounds thin and tinny.
Record With A Compressor
Sure, recording with a compressor probably raises the noise floor of your signal. But, it’s going to increase the signal-to-noise ratio at a greater rate. How?
Let me explain!
When applying compression to the signal before it enters the preamps, you’re raising the RMS (averaged) value of your signal.
RMS? In short, it’s a value used to represent the overall loudness of a sound, and the average level of the signal over time.
A compressor will even out the dynamics of the signal by making the soft parts louder, and the louder parts quieter. What you’re doing is minimizing the height of amplitude peaks so that they’re closer to the average.
Hence, you’re able to increase the average level and still leave headroom when turning up the make-up gain.
How To Gain Stage When Mixing
Attenuate Instead Of Boosting
It makes sense to boost frequencies if you want them to be heard in a mix.
However, it’s much safer to sculpt the track with what we call “subtractive equalization”.
Meaning? You cut frequencies you don’t want to be heard.
By doing so, your desired frequencies will get more space and be more prominent.
But that’s not the only reason!
When you boost a frequency, you’re also boosting the noise floor. So, if you have any background hiss in your signal, it’s going to be intensified along with the frequencies you’re trying to boost.
Obviously, you shouldn’t attenuate so drastically that you’d need to raise the fader to keep the volumes intact. This would raise the noise floor as well.
Speaking of attenuating frequencies – your track will be quieter if you’re cutting too much in the low end of the frequency spectrum. You also need to adjust for that loss and turn that gain back up.
A LUFS plugin can help you monitor any changes in your mix’s loudness. Simply bypass your EQ, take note of the LUFS reading and increase/decrease the gain subsequently.
If Needed, Attenuate Your Plug-In’s Output
Gain staging isn’t only something you do before hitting the record button. Actually, it’s a good habit to keep throughout the mixing process.
Plugins are particularly nasty in this regard.
You’ll often find plug-ins with a ton of different parameters, and some of them have really wide ranges.
That means you need to be careful about how much output gain you’re adding (or subtracting) from your plug-in chain.
You see, most plugins have their own output gain control, giving mixing engineers the ability to control how it affects the signal level at that point in the chain.
A lot of times, you’ll see a plugin with a very high output gain, and it takes up a lot of real estate on your channel strip.
Besides, decreasing the output gain won’t affect any fader automation.
Here is an example:
Let’s say you’ve inserted a compressor on your kick drum track.
If you have a 10 dB output gain on the compressor, and your kick is hitting that compressor at -6dBFS (0dBV), then you’re adding 16 dB of gain to that channel.
Furthermore, you should be able to see how much of that gain you’re adding to your audio.
Remember, the level on that individual track should still be averaging around -18 dBFS when the plugin is active.
Keep Track Of Your Sends And Returns
First, let’s start by discussing sends and returns!
A send track is an auxiliary audio track that is used to route signals to external processing devices. The most common use for a send track is to send a signal to an effects processor, such as a reverb unit or a delay line.
A return track is a separate audio track that is used to route the signal from an external processor back into the mixer. This allows the engineer to have more control over the processed signal and can be used to create different effects.
When it comes to gain staging, Send and Return Tracks are often overlooked. Why?
Because they’re not part of the main mix. They’re used for effect processing, like reverb and delay.
When you’re mixing and trying to reach a target loudness, it’s easy to forget that your effects are adding gain to your audio.
Yet, it is important to remember that Send and Return Tracks are still part of your signal path. This means that if you have a loud Return Track, there’s a chance that it could be clipping your audio.
Analog vs. Digital Gain Staging
Although the overall goal is the same when gain staging in the digital domain vs. the analog realm, it differs quite a bit.
The first thing to keep in mind is that digital and analog systems measure gain differently.
0 dBu (decibels unloaded) in the analog world is equivalent to -18 dBFS (decibels full scale) in the digital world.
In modern digital audio processing, the audio signal is represented by a stream of numbers instead of an electrical voltage.
Analog gear has physical limits on where the signal can be pushed. The internal circuits can only take so much before they saturate and begin to soft clip.
You have no physical limits in the digital realm, as the signal is merely a number.
Still, there is a ceiling we call 0 dBFS. As previously mentioned, if your digital signal exceeds 0 dBFS, you’re running the risk of digital clipping.
Analog Gain Staging
Gain staging with analog gear utilizes something called fixed-point digital processing.
In this type of processing, the level of each stage is set using a fixed number of bits. This results in a more predictable and consistent sound quality, but can sometimes result in lower overall fidelity.
As an example, saturation emerges if you’re cranking a tube amp and overloading its physical components.
Now, that colorization might be what you’re after. However, it’s not ideal if you’re gain staging and want a clean signal throughout your signal chain.
Keep these levels in mind when working with analog dBu:
- Analog clipping: +24 dBu
- Average peak levels: +12 dBu
Digital Gain Staging
DAWs utilize floating-point digital processing, often 32-bit or 64-bit.
This is a relatively new technology that offers significant advantages over traditional fixed-point processing.
In particular, floating-point processing can provide much higher levels of accuracy and headroom, which are essential for gain staging.
When gain staging in the digital domain, the only place where distortion can occur is on the inputs and outputs.
That’s where your analog stages are. In other words, the A/D-converters and D/A-converters!
Remember, if you keep your levels at 0 dBu in your DAW, you’re hitting your preamp’s output at -18 dBFS!
Keep these levels in mind when working with digital dBFS:
- Digital clipping: 0 dBFS
- Average peak levels: -12 dBFS
Leave Headroom For Mastering
When mastering audio for CDs or other digital formats, engineers need to ensure that there is enough headroom so that the music sounds loud and clear without any clipping or other distortion.
This headroom allows for temporary spikes in level without clipping, giving the mastering engineer some leeway when it comes to boosting levels during the mastering process.
While the headroom can be adjusted during the recording and mixing stages, it’s typically left at around -6 dB for mastering. You should always keep the master channel fader at 0 dB.
This gives the engineer plenty of room to work with when it comes to EQing and compression without running into any digital clipping.
Gain staging might not be the most exciting part of the production process but it will make a noticeable difference in the final product.
As we’ve seen, the process is actually quite simple.
Maintain your average signal levels at -18 dBFS and the peaks at -10dBFS!
To rock gain staging you just be aware of how each piece of gear and plugin affects the overall signal levels, and adjust correspondingly.
You need to make sure that your preamp’s output is at the correct levels. That means you’re hitting the input of the next piece of gear in the chain at the right level.
And don’t forget, leave some headroom for your mastering engineer.