An aux send lets you route any channel strip to multiple destinations without altering the main mix. This routing engine is the backbone of monitor systems, processing chains, and multi-zone playback in live sound and recording studios.
Whether you are setting up a compact PA for a club or a touring rig for a stadium, understanding how aux sends work helps you keep mixes consistent and performers confident on stage.
| Signal Role | Common Use | Output Type | Control Level |
|---|---|---|---|
| Parallel processing | Stage monitors, reverb, delay | Line level | Per channel fader and knob |
| Sidechain trigger | Gate ducking, pump effects | Derived from mix | Send amount per channel |
| Pre-fader listen | Talkback, cue mixes | Aux bus output | Independent of main mix |
| Multi-zone playback | Background music, hold music | Stereo subgroups | Bus level and pan controls |
How aux sends shape stage monitoring and foldback
On most mixers, each channel has a knob that sets how much of the signal is routed to the aux buses. In live shows, that signal becomes the feed for in-ear monitors and stage wedges, letting artists hear themselves and the band at proper levels.
Because many consoles offer pre-fader sends, performers can maintain a consistent monitor blend even when the FOH engineer rides the main fader up or down for dynamic range control during a song.
Using aux groups for monitor sections also simplifies scene changes. You can store different mixes for different songs or set pieces, then recall them quickly while keeping the front-of-house balance intact.
Using aux sends for effects and parallel processing
Reverb, delay, and distortion are often applied on aux buses so multiple sources share one processing chain. This approach preserves rhythmic precision, matches spatial width, and reduces CPU load in digital consoles and plug-ins.
Common practice is to set the send level first, then adjust the effect return to taste. Because the effect is post-fader on the aux bus, the amount of wet signal stays balanced relative to the dry signal as you automate the main mix.
For drums, you might route overheads and room mics to a single reverb aux to create cohesive depth, while kick and snare stay dry for clarity and impact in the main mix.
Routing aux sends to processing chains and external gear
Beyond monitors and effects, aux sends can drive external processors, such as compressors, EQs, or hardware exciters. Many live engineers patch aux returns into the mains to add selected coloration without touching the core mix.
In broadcast environments, aux outputs often feed cue systems, talkback processors, and recording devices independently of the main program bus. This isolation protects critical infrastructure from level changes made for audience listening.
Careful gain staging at each hop keeps noise low and headroom healthy, especially when splitting the same signal to multiple destinations with different sensitivity requirements.
Pre-fader versus post-fader behavior and creative applications
Choosing pre-fader or post-fader for each aux determines whether the send follows channel automation. Talkback and click tracks are usually pre-fader so they remain clear when the engineer ducks music, while creative effects are often post-fader to move naturally with the performance.
Some consoles allow voltage control or expression pedal control of aux levels, opening the door to real-time filter sweeps, dynamic delays, and responsive monitor changes triggered by footswitches.
By layering multiple aux buses with different processing, you can craft immersive atmospheres for ambient passages and then strip them back for vocal-forward sections without rewriting the entire scene.
Key takeaways for reliable aux send workflows
- Use pre-fader aux sends for stage monitors and talkback to maintain consistent blends during FOH automation.
- Share a single reverb or delay aux across multiple sources to create cohesive depth and save CPU power.
- Route aux returns into subgroups or external processors with careful gain staging to avoid unwanted distortion.
- Leverage post-fader sends for effects that should move naturally with the performance and fade with the main mix.
- Document your aux routing in show templates so transitions between songs and scenes remain fast and predictable.
FAQ
Reader questions
How do I prevent feedback when using stage monitor aux sends?
Keep monitors at conservative levels, point wedges away from microphones, use in-ear systems when possible, and apply notch filters on feedback-prone frequencies in the monitor path.
Can I use aux sends to create submixes for multitrack recording?
Yes, by routing drums, vocals, and guitars to dedicated aux buses you can record cohesive subgroups that simplify mixing while preserving the option to process individual mics later.
What is the difference between aux sends and direct outs in a live console? Direct outs are typically post-EQ, post-dynamics, and fixed at line level for main mixes, while aux sends are often pre-fader and provide variable amounts of signal for monitors, effects, and processing chains. How should I set gain staging for an aux send chain with reverb and delay?
Set the console output to around −18 dBFS to −12 dBFS, drive the reverb unit evenly, then match the return level so the main mix retains clear transients without clipping the bus.