Definition
Send — A mixer routing function that duplicates a channel's audio signal and routes the copy to a separate auxiliary bus, typically for shared effects processing like reverb, delay, or parallel compression, while the original signal continues to its main output unaffected.
Send Explained
A send creates a copy of a channel's audio and routes it to a different destination, usually an auxiliary (aux) bus with an effect loaded on it. The original channel continues to play through its normal output completely dry. The copy arrives at the aux bus, gets processed by whatever effect is loaded there, and the processed signal is mixed back into the overall mix at a controlled level.
The send level control determines how much of the channel's signal is sent to the aux bus. Turning the send up sends more signal, resulting in a louder processed effect. Turning it down sends less, creating a subtler effect. This gives you independent control over the effect level for every channel that feeds into the same bus.
This approach is called parallel processing because the dry (original) and wet (processed) signals run alongside each other and are combined at the output stage. It contrasts with insert processing, where an effect is placed directly in a channel's signal path and processes the entire signal in series. Both approaches have their place, but sends are essential for time-based effects and shared processing.
How Producers Use It
The most common send configuration is a shared reverb bus. Create an aux bus, load a reverb plugin set to 100% wet, and send multiple channels to it at different levels. Your snare might have a high send level for a prominent reverb tail, while your melody has a lower send level for subtle ambience. All elements share the same reverb, placing them in a unified acoustic space while each maintains its own dry-to-wet balance.
Delay sends work the same way. A single delay bus can serve your vocal chops, synth leads, and snare, each with different send levels. This is far more efficient than loading separate delay plugins on every channel and ensures all delayed elements have consistent timing and character.
Parallel compression is another powerful send application. Send your drum bus to an aux channel with a heavily compressed compressor (high ratio, aggressive settings). Blend this compressed signal underneath the original dry drums. The result adds density and sustain without sacrificing the transient punch of the uncompressed signal. This technique is also called New York compression.
Battle Tip: Set up a reverb send and a delay send as part of your battle template before the clock starts. When time is limited, having pre-configured effect buses means you can add professional spatial depth to any element with a single knob turn instead of loading, configuring, and routing effects from scratch.