There are specific types of tracks in your DAW which are designed to accept audio effects as inserts and allow you to “send” that same effect(s) to multiple tracks in your mix. In many DAWs, these are referred to as Aux tracks. In my Ableton Live, they’re referred to as Return tracks. Regardless, these tracks can be very useful for saving processing power, saving you time, and creating a more cohesive sounding mix, so let’s talk how to use Aux send tracks in your mix.
How to Use Aux Send Tracks
Let’s go step by step to easily show how to use aux send tracks in your mix, more about why they’re so useful, and lastly a few suggested effects to use as aux sends.
Step 1 – Create an Aux Track
Before we can do anything, we need to create an aux track which we’ll dedicate an audio effort or multiple audio effects to which we can then apply to various tracks in our mix.
Different DAWs have different ways of creating these tracks. The default template in your DAW may already have some aux tracks ready to receive an audio effect or effects.
In my Ableton Live, the default template has a two return (aux) tracks pre-populated each with a delay and reverb effect, respectively.
Of course every time I open a new set it defaults on my custom mixing template, but I have a number of return tracks which have effects I like to use in most mixes, so in the interest of saving time I have those all set up and ready to go with every new set I open.
In Ableton Live on Windows, the shortcut of Ctrl+Alt+T creates a new blank return track which is ready to accept an audio effect of your choice. Speaking of which…
Step 2 – Drop an Audio Effect on that Aux Track as an Insert
This next step is as simple as the first (with one important reminder).
You simply drop/insert the audio effect that you want to apply to individual audio tracks in your mix directly on the aux track itself.
For instance, if you know that you want to apply a reverb track multiple tracks in your mix, drop your reverb of choice on that aux track.
REMEMBER that whenever using an audio effect as an aux send, set the wet/dry to 100% wet (when applicable).
As I covered in my comparison of inserts vs sends, with aux sends we’re using the send dial (which we’ll talk about in the next step) as the blend amount with the dry track.
With that in mind, we want this aux track to represent 100% or exclusively that effect, so set that wet/dry on the reverb in this example to 100% wet.
Just one more reminder, whenever you put an audio effect on an aux/return track, make sure if it has a wet/dry percentage controller, keep it on 100% wet.
Step 3 – Blend In Your Desired Amount Via Specific Track Send Dials
Now that we’ve got the effect we want on an aux track and it’s set to 100% wet, we can use the send dial for the respective tracks we want to apply that effect to as the specific wet/dry dial for the effect’s impact on that track.
So if we want to apply that reverb to a vocal track, we’d simply turn up the unique send dial for that aux track on that vocal track.
Ableton Live labels these consecutively as “A”, “B”, “C”, etc. every time you create a new aux/return track and adds another corresponding dial to every track in the mix for you to adjust.
You’ll notice that the higher you turn that aux track’s send dial on the vocal track (in this example), you’ll hear more of that reverb asserting itself in the mix on that vocal.
You’re actually hearing a completely separate instance of that vocal, one which is soaked in that reverb, blending with the original dry vocal.
Some effects you just want a taste of to where you “feel” them more than you hear them when toggling them on and off in the mix. Others like the reverb you might want a couple more dB on those aux send dials; it’s really to taste.
That’s the extent of how to use aux send tracks in your mix, though. The beauty of them again is that they allow you to apply the same effect to multiple tracks.
This is beneficial both because it saves you time from having to set up the same instance of the plugin on multiple tracks, not to mention it saves mixing CPU power.
Perhaps more importantly, this gives every track in your mix which you apply that effect to via their respective send dials a common sound which adds a sense of cohesion to those tracks and your mix as a whole.
With a spacial effect like reverb, this makes those tracks sound like they’re existing in the same space which is a nice touch especially when you were recording those tracks in different spaces or are using a lot of DI tracks which don’t have an innate sense of character to them like live space recorded, meaning microphone recorded, tracks have.
Recommended Audio Effects to Use as Aux Sends
Lastly, let’s cover a few of the best audio effects to use as aux sends.
Reverb
We just talked about this, but reverb is one of the best effects to use as aux sends because, as I just mentioned, it gives every track you apply it to that sense of cohesion between them.
This is better than using a dozen different reverbs with different settings which are replicating larger or smaller rooms, making the various tracks sound like they’re originating from all over the place.
With aux sends, I like to simply set up two different reverbs, a shorter one and a larger one. The shorter reverb delivers some width and a touch of depth, the longer reverb focuses on more depth.
I can then automate that longer reverb for the bigger moments in the song, either holding it back entirely or simply bringing up the level on the individual tracks in my mix until that chorus hits to make that chorus hit that much harder.
Note that you may want to follow that reverb up on that aux track with an EQ to at least high pass to get rid of the muddy, thick low end which can muddy up your mix.
Speaking of which, check out my overview of the Abbey Road Reverb Trick for tips on keeping your reverb clean while still enjoying the depth it brings to your mix.
This is a good reminder that you can follow up any audio effect on an aux track with another to create a combined sound;
Delay
Delay is great for adding some width to your tracks, as well as the illusion of some depth but without the baggage which reverbs can bring sometimes.
Likewise I like to have a shorter and narrower delay as well as a longer, wider one, and can automate them particularly on vocals between the verses and choruses.
Parallel Compression
Parallel compression is a great effect to use with aux sends because it’s a common one you’ll want to apply to multiple tracks in your mix such as the snare and vocals. Really anything which needs a bit more thickness and energy behind it, parallel compression works well.
Rather than creating duplicates of the tracks you want to parallel compress, just drop a compressor with my parallel compression settings on it, then dial in the amount you want on every individual track to taste.
This is definitely one of those “feel” it more than you hear it forms of parallel processing or uses of aux sends. Dial in just enough so that you can tell there’s a difference when it’s gone, then maybe turn the send dial down for that track 1dB.
Width
While delay as well as reverb are both nice for creating some width on your track, a very subtle way I like to do it is by dropping Soundtoys’ Microshift or Little Microshift on an aux track:
This creates a sort of modulated effect to give you some instant width on any track in your mix which feels like it needs a little more size in the stereo field.
Really any kind of modulated audio effect works well here for a similar purpose like the chorus effect, just again and as always make sure that the wet/dry is set to 100% wet so any of that aux track you blend in via send is entirely that effect to blend with your dry main track(s).
Saturation
Saturation is another great effect which you can use to warm up a number of tracks in your mix all from one aux track.
Just drop a saturation plugin of your choice (I’m partial to Decapitator from Soundtoys) on a fresh aux track to add some consistent mid frequency overtones to your tracks of choice.
Honestly any type of parallel processing you want in your mix works well via aux sends.
One last tip and/or reminder – you can also send aux tracks TO OTHER aux tracks.
Aux tracks have send dials on them like any other track. To blend in another aux track’s effect(s), simply turn up its respective dial on the aux track you want to blend that effect in with.
Note that in my Ableton Live’s case you may need to right click on the dial and select “Enable Sends” as by default, sends are turned off on aux tracks.
A common use of sending an aux track/effect to another aux track is to send a little reverb to your delay to add a little extra depth to the delay you’re already sending to tracks in your mix.
Regardless of how you mix and match, this is an effective way to bring a little extra character to your sends on top of the audio effect which is on that aux/return track.
But there you go, an overview on how to use aux sends in your mix to bring an added sense of cohesion to multiple tracks in your mix while simultaneously saving yourself time, not to mention making the load on your CPU a little lighter.
