A send takes a copy of a channel's signal and routes it, at an amount you set, to another destination, usually an effect. The return is the channel that brings that processed signal back into the mix. Together they let you run one reverb or delay and share it across many tracks, instead of loading a separate effect on every one. It is all just routing.
None of this is tied to one plugin or one DAW. The names shift between programs, so a send might be an aux send and a return might be an aux track, an FX channel or an effect return, but the idea is the same everywhere. The habits below are common starting points rather than strict rules.
A send takes a copy of a channel's signal and routes it, at an amount you set, to another destination such as an effect bus, and the return is the channel that brings that processed signal back into the mix. The original track keeps playing on its own channel at its normal level. The send is an extra tap off it, and a send knob decides how much of the track is fed down that tap. That amount is separate from the channel fader, so you can leave the track sitting where it is in the mix and still turn the send up or down on its own.
The return is the other half. It is a channel, often called a return, an aux track, an FX channel or an effect return depending on the program, and it is where the effect itself lives. The copies arriving from all your sends land on that return, pass through the reverb or delay loaded on it, and come back into the mix through the return fader. So the signal splits off at the send, gets processed on the return, and is blended back in. A send with nowhere to go does nothing on its own, because it needs a return to arrive at.
Keep the picture simple. A send does not change the track it comes from; it only branches a copy of it. Everything the effect does happens on the return, off to the side, and then gets folded back into the mix underneath the parts you already have. That side path of copy, process, blend is the whole mechanism, and once it clicks the rest is just deciding how much to send and how loud to return.
A send can tap the signal before the channel fader or after it. A post-fader send follows the fader, so when you pull the dry track down its send drops with it and the balance between dry and effect holds. That is the usual choice for reverb and delay. A pre-fader send ignores the fader, so the amount going to the send stays fixed even if you drop or mute the dry track. Pre-fader sends are useful for headphone and monitor mixes, where a player wants their own balance, and for effects you want held steady on their own.
An insert sits in the channel and processes the whole signal in series, while a send splits off a parallel copy that is processed separately and blended back in. An insert is in line: the whole signal of the track runs through the plugin and out the other side, so what you hear is the processed version and nothing else. That is what you want for anything that should shape the entire sound, like EQ, compression or saturation.
A send is parallel. The dry track keeps playing untouched on its own channel, and only a copy is peeled off and sent to the effect on the return, which is then mixed in underneath the dry. Because the original is still there, a send lets you add an effect without losing the direct sound. That suits reverb, delay and other space and texture effects, where you usually want a little of the effect sitting behind a mostly dry part rather than the whole part drenched.
This also changes how you set the wet and dry balance. On an insert you blend inside the plugin, using its own mix control, or you run it fully in line for effects like EQ that have no dry worth keeping. On a send the return is usually run fully wet, because the dry sound is already coming from the original channel, and you blend the two with the send amount and the return fader. As a rough guide, reach for an insert when the effect should change the whole sound, and a send when you want to add an effect on top and keep the dry.
Use a send when you want several tracks to share one effect, most often one reverb or delay, instead of loading a separate copy of that effect on every track. This is the classic move. You put a single reverb on one return, then turn up a send on the vocal, the guitar and a synth so a copy of each feeds that one reverb. All three now sit in the same space. It is exactly how reverb is usually handled, covered in more depth in our guide on reverb and how to use it.
That buys you three things. It saves the computer work, because one reverb is running instead of five. It glues the mix, because parts sharing one space sound as though they were played in the same room rather than each in a slightly different one. And it keeps things easy to control, because there is one effect to adjust rather than many, so a single tweak to the return moves every part at once.
When you do this, set the amount with the send knob on each track, not the channel fader, so you decide how far into the effect each part goes without changing where it sits in the mix. Run the effect on the return fully wet, since the dry sound is already coming from the tracks, and blend the return in underneath until you notice it, then ease it back. A part you want more distant gets a higher send, and a part you want up front gets less or none.
A send is not always the answer. When an effect is part of the sound of one specific part, a spring reverb that is the character of a guitar, or a delay written into a single lead, an insert on that one channel is simpler and keeps it self contained. Reach for a send when the effect is a shared space or a shared texture that more than one part should sit in.
A bus or group sums several whole tracks together so you can process them as one, while a send splits off a parallel copy of a track and routes it to an effect. The two get mixed up because both route audio to another channel, and in most programs a return is technically just a bus with an effect on it. The difference that matters is what travels down it and why.
A bus, also called a group or subgroup, carries the full signal of the tracks routed into it. Their direct outputs to the master are replaced by the group, so one fader now controls the whole section and one chain of plugins processes all of it together. The everyday example is a drum bus, where the kick, snare and the rest feed one channel so you can level the kit with a single fader and glue it with one gentle compressor. Nothing is copied, because the whole signal goes through the group. There is a fuller walk through this in our guide on bussing.
A send does the opposite of taking over the signal. It leaves the track playing where it is and peels off only a copy, which goes to an effect on a return and is blended back underneath the dry. So a group is for handling whole tracks as one unit, and a send is for feeding a copy of one or more tracks into a shared effect. If you are levelling and shaping a section together, that is a bus. If you are sharing a reverb or a delay across parts while keeping their dry sound, that is a send.
| Behaviour | Send and return | Insert | Bus or group |
|---|---|---|---|
| What travels down it | A copy of the track; the original keeps playing | The whole signal of that one track | The whole signal of every track routed in |
| Routing | Parallel, blended back under the dry | In series, in line on the channel | Replaces the tracks' direct outs and sums them to one channel |
| What it is for | Sharing one effect across tracks, like a reverb or delay | Processing one track's whole sound, like EQ or compression | Levelling and processing a group of tracks as one |
An insert changes a whole track in series. A bus sums whole tracks so you can treat them as one. A send takes a copy of a track to a shared effect and blends it back. Same idea of routing audio somewhere, three different jobs: an insert to process one part, a bus to group parts, a send to share an effect.
A send is a routing move. It carries a sound off to an effect and brings it back, but it cannot invent the sound in the first place, and a dull part fed into a lovely reverb is still a dull part. The work worth doing is making a source worth sending.
We do not make a reverb, a delay or any effect you would put on a send, and this guide is not a pitch for one. But sends and returns sit better when the sound going in already has a clear identity. The Collection is our three instruments together, ARGISH, SILT and REHEAT, with three separate licence keys. ARGISH is a self-playing chord synth, SILT is a tape-loop instrument, and REHEAT writes acid lines, and each one gives you a clean, controlled part on its own channel, the kind of source that takes an effect send well instead of turning to mush. Whatever you make with them is yours to release.
Each one ships as AU, VST3, AAX and a standalone app on macOS, signed and notarized, and a VST3 on Windows. You can hear one free in your browser first, no install and no account, then decide.
Everything on this page works by hand with the sends in any DAW, which is rather the point of writing it down.
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