Preparing your song for Mixing: Gain Staging

Have you ever found yourself working in your DAW for hours end, creating an amazing piece of music, and you’ve been mixing as you go – adding in your favourite plugins to sculpt your sound, but for some reason it just doesn’t sound clear and balanced? Its then that you notice your volume faders are all over the  place, some are pushed close to the top, while others are sitting low. Meanwhile, your level meters are also bouncing all over the place, some are red and clipping and others are barely registering. At this stage, you could persevere and hope for the best, OR you could take some timeout to reset, by reviewing and adjusting the gain stage for each track.

Gain staging is often overlooked by composers and producers and as a result, this can be largely attributed to the modern software-based production environment that can accommodate large amounts of gain before clipping, giving the perception of a loud and full mix. However this can cause problems, particularly if you are using analogue-modelling plugins, as they are not designed to operate well when presented with high-gain signals ie. “hot signals”. This can then lead to problems when it comes to bouncing your tracks to stereo, as the summing engines in you DAW do not always produce the same result as you hear in your sessions, when summing lots of high-level signals, which can be audible. This results in mixes sounding unprofessional and incomplete. NOTE: Its important to keep in mind however, that a great mix actually begins with great orchestration and arrangements.

So What Is Gain Staging?

Gain staging refers to the management and control of volume levels for any number of VST or audio signals (and subsequent plugins in their respective signal chains) contained in your DAW session, at any point with the production and mixing process, to:

  • prevent the introduction of noise and distortion

  • avoid running out of headroom on your meters, particularly on your stereo / master buss.

  • achieve the cleanest mix possible

  • better workflow practice by take control of your DAW session and get a clear understanding of the gain/SPL relationship between each track (the positioning of your faders will now provide useful feedback).

 
fig. 1 DAW mixing meter
 

Before going any further, lets quickly touch on the meaning of “gain”, which can often get confused with volume – or to use the correct term of measurement “Sound Pressure Level (SPL). Gain refers to the strength of the signal coming into a device, while SPL refers to the strength of the output leaving that device.

Because of this, it’s possible to use the gain input to increase the loudness of a device and still have a healthy signal afterwards. There is certain analogue equipment like tube compressors, that sound really nice when the signal is overdriven and comes in hot into their input circuitry; You just have to control the output afterwards to control your gain staging. For example -  below shows where a compressor has been implemented into the signal chain – the sound processed through compressor has significantly increased its volume by some 12dB, so to keep the same signal strength coming into the compressor, we need to reduce the output SPL by 12dB to keep control of our gain stage.

 
2. Compressor .png
 

Be aware that digital an analog systems measure audio differently. In your DAW, gain is measured in terms of dBFS (decibels full scale). And this is why a good rule of thumb to remember is -18 dBFS in you DAW (at 24 bit) is roughly equal to 0 dB in the analogue domain.

 Therefore having your level meters sitting anywhere between -20 and -16 dBFS (on average) is a good optimum range when your level fader is sitting at “Unity Gain”, that will leave sufficient headroom further down the signal chain (ie instrument busses), and eventually your stereo / master buss.

 NOTE: Its not uncommon to see track level meters hitting -12 dbFS, which is still within the “green” of your level meter. This is fine, but keep in mind, if you gain stage tracks at this level, the head room in your stereo / master buss will disappear much quicker, so this will require closer vigilance of your stereo output meter. Also remember that the point of gain staging is to achieve the cleanest mix possible, not the loudest. Loudness can be compensated for in the mastering stage, a clean mix cannot.

One last concept to understand is the term Unity Gain. Unity Gain refers to when a device such as a fader or level control is neither cutting or boosting the incoming signal. To achieve Unity Gain, the output  signal level must be equal to the input signal level.

 
3. Example A.png
 

3 common ways to Gain Stage (prior to any plugins being installed on your signal chain are:

  • Clip / Region gain control: affecting the region/clip wave from directly

 
4. Region -Clip.png
 

  • A Gain Utility Plugin: placed as the first plugin, effects the strength of the gain signal as it enters the channel

 
5. Gain Plugin.png
 

  • VST output volume: for midi date performed by a VST (refer to the Spitfire Audio VST pictured above).

The video below demonstrates how to implement these methods in the Logic Pro X environment.   DAWs such as Pro Tools, Cubase, Ableton, Digital Performer etc will have similar functionality and plugins available.

 
 

Summary

These gain staging tips are a guide to get you started only. There is a wealth of information out there that provide more in depth and technical information if you feel inclined to investigate further, which I would encourage you to do. Sound on sound has a fantastic comprehensive article on the more technical aspects (https://www.soundonsound.com/techniques/gain-staging-your-daw-software),  and pro Audio Engineer Warren Huart provides a great overview history of where gain staging came from, how its changed in the digital realm, and his 3 biggest tips for getting it right.