Effects & processing
Send and return
A send takes a copy of a signal to an external effect; the return brings the processed version back into the mix. The original keeps playing, so the effect is added alongside rather than replacing it.
In practice
A send leaves the dry track playing, which is why an effect on a send can never make a record disappear.
Use sends for anything that should sit around the music — reverb, delay, a long echo — and inserts for anything that should replace it, which is most filters and any dynamics. On a return, high-pass the effect rather than the source: it keeps the wash out of the low end without thinning the record that fed it. And set the effect fully wet at the unit, because the dry half is already in the mix and doubling it is what makes a send sound louder rather than deeper.
A copy
What a send takes
100% wet
How to set the unit
High-pass it
What to do at the return
Where these come from: Signal-routing conventions, not catalog figures. For what we can measure, see the balance this changes the meaning of.
Why it matters
The distinction that matters is copy versus replace. An insert puts the effect in the signal path, so anything it does to the sound is what you hear; a send leaves the dry track running underneath, which is why a send effect can never make a record disappear no matter how far you push it.
It also lets one effect serve several channels. A single reverb on a send can be fed from both decks at whatever amounts you choose, which is both cheaper and more controllable than a separate unit per channel.
Frequently asked
What is the difference between a send and an insert?+
A send copies the signal to an effect and mixes the result back in alongside the original. An insert puts the effect in the path, so the processed signal replaces the original entirely.
Should a send effect be fully wet?+
Yes. The dry signal is already in the mix through the channel, so any dry level at the unit is a second copy of the same thing, which reads as extra volume rather than extra effect.
Do DJ mixers have sends?+
Most club mixers have at least one send-and-return pair, which is how an external effects unit or a laptop gets into the signal path without being inserted on a channel.
Related terms
Wet/dry
Wet is the processed signal, dry is the untouched original. The wet/dry control sets how much of each you hear, and on most DJ effects it is the only depth control there is.
Reverb
Reverb is the sound of a space — hundreds of reflections arriving after a sound and fading. As a DJ effect it is used to smear the tail of one record into the arrival of the next.
Delay
Delay repeats a sound after a set time. On a DJ mixer that time is locked to the detected tempo, so the setting is a beat division rather than a number of milliseconds and the repeats land on the grid.
Beat FX
Beat FX are the effects section on a DJ mixer that locks its timing to the detected tempo. Every delay, echo, roll and gate is set in beat divisions rather than in milliseconds, so one setting stays musical across records.
Explore: Mixing guides · Reverb · Wet/dry · All DJ terms