The vocal bus can be used to make macro level adjustments to your vocals with a single effect. Arguably the most effective and practical effect to use here is vocal bus compression, so let’s talk the best settings to help create cohesion between all of your vocals.
Vocal Bus Compression
There are many types of audio compressors. When it comes to compressing MULTIPLE tracks at once as is the case on a bus, I prefer a VCA, or Voltage Controlled Amplifier compressor which especially excel on busses.
VCA compressors balance low distortion, can attack quickly when necessary, and most important offer up some of the most transparent compression.
Many VCA style compressors are referred to as glue compressors because of their knack for creating the sought after cohesion that we want between multiple tracks.
The trick is to avoid being too aggressive with a glue compressor on your vocal bus so that you erase any individuality or punch between the vocals.
Many DAWs come with a stock glue compressor. My DAW of choice, Ableton Live, has had a very capable and simply titled “Glue Compressor” for the last several versions now.
My go-to glue compressor is the Waves SSL G Master Bus Compressor.
Regardless, most of them have a very similar looking interface with the exact same parameters.
Here is a snapshot of the vocal bus compression settings I like to use when compressing my vocal bus with a glue compressor:
Let’s briefly go through each setting here to better convey why everything is set where it is.
Threshold
The compessor threshold determines how much of that vocal in terms of level is being compressed.
Remember the curve ball here is that every single vocal in our mix is affecting and flowing into this.
As such, when using vocal bus compression it’s important to use the loudest COMBINED moment in your entire mix vocally to set the threshold.
If you don’t, you’ll set the threshold too low. The effect will be that when that combined vocal peak hits with your lead, its doubles, and harmonies all going at once during the chorus, the entire vocal will be compressed more than you intended.
One last thing to mention is that the actual compression is a product of every parameter, not just threshold, so you’ll need to adjust these settings on the fly until you get the right combination. This is why these vocal bus compression settings work well.
Less is more whenever you’re adding any kind of processing to a bus, so you likely only want to aim for 1-3dB at most of gain reduction at the busiest/loudest vocal instances of your track with the rest of these settings in place.
Ratio
The compressor’s ratio determines to what degree the peaks of the audio which exceeds the threshold is compressed/turned down.
2:1, meaning every 2dB which exceed the threshold are reduced to 1, is a light ratio which works well on vocal bus compression because we just want to gently smooth out the combined dynamics of the vocal.
We should’ve tamed all of the individual dynamics from our individual vocal tracks previously (see my vocal compressor settings cheat sheet) using higher ratios. Here we’re just trying to create a little cohesion with the combined sum of all of these already compressed tracks, and 2:1 is a gentle and transparent way to do just that.
If your combined vocal is still too dynamic, you may need to revisit their compression settings on a track level or bring down their faders in the context of the mix.
Attack
Compressor attack is how fast that compression begins once the threshold is exceeded. Set it too slowly and the compressor won’t engage when we want it. Set it too fast/short and we’ll pull out the transients and life from our vocal.
3ms is a good attack time for letting the transient punch of the consonants of your vocal come through while still enjoying the benefits of the compression, even on a bus level.
Release
Release is the offramp for the compressor, also measured in milliseconds.
I really like the automatic release on the Waves SSL G Master Bus Compressor for complex dynamics like I get from a vocal bus for letting that compressor release the vocal once it drops below the threshold reactively as necessary.
Gain
Lastly, the output gain determines the output level post compression.
Use this to manually correct the level of your vocal bus which will mean adding back in couple few decibels to offset the drop from the compression.
The idea isn’t to make the vocal bus quieter or louder after the compression, so ensure what goes in matches what comes out by adjusting it then A/B split testing it with it on and off to ensure you’ve got it set right.
It’s as simple as that!
While it’s certainly not necessary, you may find that adding a compressor, particularly a glue VCA style compressor, to your vocal bus can help smooth out the dynamics and make that combined vocal sound more powerful and gel together better in the context of the entire mix at the cost of a small touch of dynamic range.
Remember that less is always more when it comes to bus processing, and that extends to compression like anything else, so don’t overdo it!
