What is gain staging?
Gain staging is level management. It comes from the analogue days where it was essential to get a good signal-to-noise ratio whilst preventing clipping the channel. Of course, many like the sound of clipping analogue gear but that’s a whole other thing! Gain staging was also very necessary to make sure that the level going into each hardware unit was optimal. Arguably it’s less important when working in a DAW, but it’s still very good practice especially if the plug-ins you use model the properties of analogue gear.
In my opinion, using pre-fader metering in Logic Pro is essential to practice good level management. With pre-fader metering on, the levels indicated in Logic’s mixer are pre-fader, meaning the levels are what they were before being adjusted by the fader. The fader is in itself a gain stage. However, if we remain in post-fader mode (default), we may be unaware of how hot those levels were before the fader adjusted them. For example, if the level shows -10 dBFS, but our fader is at -10dB, that means the level before fader is at 0dBFS, which could be giving the plugins we use on that channel a very hard time. This is especially true if any of them are dynamics processors such as compression. This is why it’s essential to practice proper gain-staging well before we enter the actual mix phase and certainly before we use any compression.
How To Gain Stage
So with pre-fader metering on, we know the level of the tracks even with the fader all the way down. From here we can do some simple pre-mix housekeeping. Now, Logic’s meters are peak as opposed to RMS, so I recommend that you make sure all of your levels are in the green zone roughly -12dBFS or below.
Gain Staging Software Instruments
Like most things in audio, it’s best to fix the issue at source. At least as early in the signal flow as possible anyway. When it comes to synth/MIDI tracks, I advise using the volume control of the software instrument/synth itself to get the meter into the green zone.
Gain Staging Audio Tracks
Attaining the ideal level in your audio tracks is as easy as using the clip-gain feature in the region inspector. I would play the track through, get a rough idea of the level at which it is peaking, and simply apply the maths to the gain control in the inspector with all of the regions on that track selected. See below.
Now it’s too quiet!
This is where you will need to adjust your monitoring. It’s important that you calibrate your monitoring properly otherwise it’s difficult for your ears to know exactly what loud is. I recommend you look into using the K-System, or for a very quick and easy way to do this, I wrote a blog on how to do this simply using Spotify.
Now that you have calibrated your monitoring, it will be near impossible to overcook the mix as anything louder than -10dBFS RMS will be loud to your ears, forcing you to practice decent level management. Now that -10dBFS RMS is loud to your ear, you will always preserve the range above that for peaks and transients. You’ll never overcook your mix again!
The Master Bus
So now you have properly managed your levels and you have created a nice balance using the faders. But you’re thinking the mix is a little too quiet to your ears. Don’t adjust your monitoring. If it’s still too quiet at this point, it’s very likely you have some headroom on your master bus. The solution is as simple as loading a Gain utility (Logic stock plug-in) on the master bus (Stereo Out) and raising the volume of the mix from there. You should be able to get it loud enough that you can hear it comfortably whilst preventing the channel from clipping.
Reaching the song’s loudness potential
So your mix is well balanced and the level on the master bus is close enough to 0dBFS without clipping. But it’s yet to reach it’s full loudness potential. You may be tempted to use some dynamics processing on the master bus to increase perceived loudness. I suggest however that you bounce out to 24 bit and do all of this in a separate mastering session if you are going to do it yourself.
The below video is a tutorial on gain-staging I made some time ago for Logic Pro X. It covers most of the above. Happy gain-staging!