If you’ve read the article, ‘A tried and tested DAW workflow for mixing sessions’, you’ll already know the benefit of setting up instrument buses. Using a drum bus, guitar bus or vocal bus opens up a great deal of flexibility and control in your session.
Why use a drum bus, vocal bus or guitar bus?
When mixing, it really helps if you set up separate auxiliary tracks to control each of the groups of instruments. An auxiliary track is a channel that acts as a control point for each of the signals routed to it. I generally set up an auxiliary track to control all of the drum’s audio tracks. I do the same for all of the guitar’s audio tracks, the vocal tracks etc. You can do this for any group of instruments. You could set one up for all of the keys, all of the percussion, all of the strings etc. Audio signals are sent, or ‘bussed’, to these auxiliary tracks, which is why they are referred to as a drum ‘bus’ or guitar ‘bus’.
The ability to monitor and control all of the audio signals for one instrument on an auxiliary track is really helpful. It means that once you’ve balanced the level of the kick, snare, overheads etc. you can control the kit’s overall volume from just one fader. The same is true for the level of all of the guitar amps, or all of the vocals for instance. What’s more, you can apply compression, EQ or any other plugin to all of drums, guitars or vocals at once.
Setting up a drum bus, guitar bus or vocal bus
In this article I will demonstrate the process using ProTools, but this same process works in any DAW. Begin by setting up some auxiliary tracks, one for each instrument bus that you want to create:
Routing audio signal outputs to aux track inputs
To route the signals of each audio track to the relevant auxiliary track, assign the output of each to a designated bus. Use one bus for all of the drums, then a different bus for all of the guitars, a different one for all of the vocals etc. Now, the assigned buses are sending out each of those signals.
Numbers usually represent buses by default, but they can easily be renamed. By giving them names, it makes it easier to set up the routing in your DAW.
Routing auxiliary track inputs to audio signal outputs
Set the input of each of the auxiliary tracks to the bus which is sending out that instrument’s audio signals. Don’t forget to also route the output of these auxiliary tracks to your mix bus or master fader:
Now, all of your audio tracks first pass through an auxiliary track before they reach the mix bus. This means that you can apply EQ, compression or effects to each instrument as a whole, not just on the audio tracks. You can see an example of this here, as EQ is present on the drum bus as well as on each of the kit’s audio tracks:
In the above example, compression is not present on either of the bass guitar audio tracks. Instead, compression is active on the ‘bass bus’ aux track. This way, compression is being applied to both bass guitar tracks at the same time. The same is true of the EQ. Here, EQ is being applied to one of the bass guitar audio tracks to take out a problematic frequency. Then, further equalisation is active on the bass bus to make the instrument’s frequency response better suited to the mix as a whole. EQ is not present on the guitar bus aux track. Instead, EQ and compression are present on the audio tracks. Conversely, the vocal bus receives all of the processing, and non is carried out on the individual vocal audio tracks.
The flexibility of instrument aux tracks
As you can see, routing the signals this way gives you a great deal of flexibility in your mixing. For some, the ability to add overall control to groups of instruments is the greatest benefit. For others, the ability to add plugins to instruments as a whole offers the biggest advantage. But for most, a combination of the two is what makes this a winning process. Open up a session and give it a try!