What is a Send (Aux Send)?

A send, often called an aux send or auxiliary send, is a control on a mixer or digital audio workstation that routes a portion of an audio signal from a channel to another destination, such as an effects processor or monitor mix.

Aux sends are commonly used to send audio to reverb, delay, or other effects units, allowing multiple tracks to share the same effect. The amount of signal sent can be adjusted independently from the main channel level.

Sends are also widely used to create monitor mixes for performers during recording or live performances. By adjusting aux send levels, engineers can create separate mixes for stage monitors or headphones without affecting the main mix heard by the audience.