Maybe you use return tracks, maybe you don't. In the mixing environment of a DAW sends and returns can seem anachronistic. Nonetheless there are great reasons to use return tracks. In this article we will talk about how you can use return tracks to improve your mix and when it may be better to use a different method of processing.
First off audio effects are loosely broken down into two categories, insert effects and return effects. Insert effects are placed on individual tracks in your mix. For example, if you were to put Saturator on your kick drum track the distortion plugin would be a insert effect. Return effects live on separate tracks called return tracks and can be applied to more than one audio or MIDI track at a time. To use return tracks you have to send an audio signal from the track you want to process to the return track using a send knob. As you crank the send knob more and more of the processed signal will be heard.
Return tracks come from the days before computers were used the studio. Engineers would mix on a mixing board and use analog devices to process the audio signals. Analog devices were expensive or large and often a studio would only have a single type of a certain effect processor, imagine a plate reverb. If the engineer had one plate reverb device and he/she wanted to apply it to more than more element in the mix he/she wouldn't have been able to do it without return tracks. The send knobs allowed the engineer to send part of the drum signal, part of the vocal signal, part of the keyboard signal, and part of the guitar signal to the plate reverb thus affecting all of the different parts simultaneously. Not only did this save money but using the same effects on several tracks had a beneficial sonic outcome. For example, a reverb or delay return track helps create an acoustically cohesive space for your song.
Fast forward today and we can see that the benefits return tracks persist. Using a return track with reverb will help to glue the tracks in your song together and allow it to create a realistic sounding acoustic space. Duplicating audio effects is simple in a DAW but utilizing a pastiche of different reverb settings on separate tracks in your song will create a song that couldn't possible exist in a real space and may even disorient your listeners. Although duplicating high quality convolution reverbs onto every track in your mix won't cost you any money, it will cost you CPU power, lots of it. Using return tracks will help reduce CPU load while you produce.
Despite all the benefits of using return tracks there may be times you don't want to use them. Sometimes it make more sense to use an insert effect instead of a return track. For example, say you only plan to use an effect on a single track, there is no sense in creating a dedicated return track for it. Or maybe you want to automate a parameter on the effect without affecting the sound of multiple tracks. If you choose you can even use the insert effect like a return track if you put it into an Audio Effect Rack:
Once you have the audio effect rack setup you can go even deeper and make your own Dry/Wet knob which is a helpful trick when you're dealing with plugins that don't have a dry/wet knob builtin i.e. Redux. Start off by making two chains. One chain will be called 'Wet' and will contain an effect set to 100% Wet. The other chain will be called 'Dry' and will not contain any effects. The next step is to open up the chain selector window and distribute the ranges of the two chains from 0 to 127. After you have distributed the ranges you will make use of the crossfade function of the zone editior. Start with the 'Dry' chain and grab the zone editor, the thin bar above the main zone bar, and drag it across. Start on the left side. Then do the same to the 'Wet' chain but start from the right side. The final step is to map the orange chain selector to a knob to a macro on your Audio Effect Rack. Rename the macro Dry/Wet and you're good to go.