Pre-Fader vs Post-Fader Aux Sends: Live Sound Routing Explained

TL;DR — A pre-fader aux send does not follow that channel's main mix fader; a post-fader send does. Pre-fader routing is common when a monitor or utility mix needs independent level control. Post-fader routing is common when an effects send should track the main mix. Neither choice defines whether the signal is before or after EQ, dynamics, mute, or delay. Confirm the console's pickoff point, then document every destination and test its behavior.

Table of contents

1. Understand the fader relationship
2. Choose pre-fader or post-fader by destination
3. Separate pre/post from the pickoff point
4. Build and test an aux routing plan
5. Document sends in the rider
6. FAQ

Understand the fader relationship

Pre-fader and post-fader describe whether a channel's send to another mix is independent of or affected by its main mix fader. The terms describe a control relationship, not the complete location of the signal tap.

Imagine one vocal channel feeding the main left/right mix and an auxiliary mix:

• with a pre-fader aux, moving the vocal's main mix fader does not change the send level to that aux;
• with a post-fader aux, moving the main mix fader changes the level sent to that aux too.

The aux send control still sets how much of the channel enters the aux. The aux master controls the resulting mix output. Assignment, mute, DCA, processing, and source-point behavior depend on the console and configuration.

Use the routing screen, block diagram, or manual for the actual console. Labels such as PRE, POST, AUX, MIX, or BUS are not enough to establish the complete signal path.

Aux, mix, bus, and send

A bus combines signals inside a mixer. An auxiliary mix is a bus commonly used for monitors, effects, zones, recording, streaming, or other independent outputs. A channel send determines whether and how much that channel feeds the bus.

Digital consoles may call the destination an aux, mix, flex bus, or mix bus. The useful question is the same: where is the channel signal taken, which controls affect it, and where does the bus output go?

Choose pre-fader or post-fader by destination

Choose behavior from the destination's job instead of copying a generic console template.

Monitor mixes

Pre-fader sends are common when FOH is also building stage monitors. The FOH engineer can change the audience mix without automatically changing the performer's aux level. This does not make the monitor mix completely independent: shared preamp gain, channel processing, mute behavior, and the configured pickoff point may still affect it.

A dedicated monitor console may use a different workflow. Its channel faders can act as the primary controls for the selected monitor mix, and console configuration determines what “pre” and “post” mean in that operating mode. Document the outcome rather than assuming every monitor send must display the same setting.

Use the monitor mix guide for destination planning and the monitor console tech rider for split, output, talkback, and show-file handoffs.

Effects sends

Post-fader sends are common for time-based effects such as reverb or delay. When the dry channel is lowered in the main mix, its effect send follows, preserving the intended dry/effect relationship. The effect processor output returns to another channel or return path that is blended into the destination mix.

Check routing carefully to avoid feeding an effect return back into the same effect send unintentionally. That loop can create escalating repeats or feedback. Creative feedback effects are a deliberate exception, not a safe default.

Recording, streaming, broadcast, and press feeds

There is no universal pre/post choice for an external program:

• a simple reference recording may intentionally follow the main mix;
• an isolated track normally should not follow FOH fader moves;
• a stream or broadcast mix may require independent channel balance and processing;
• a lobby, backstage, assistive-listening, or press feed may need a specifically edited mix.

Define the deliverable first. Then choose the send point and control relationship that produces it. The multitrack recording tech rider and livestream audio tech rider cover those destination-specific decisions.

A destination decision table

“Likely” is not a specification. Confirm the actual console, show file, crew, and destination.

Separate pre/post from the pickoff point

Pre-fader does not automatically mean pre-EQ, pre-compressor, pre-mute, or immediately after the preamp. A console can offer a source-point choice and a separate pre/post-fader choice.

A simplified channel can contain:

preamp → high-pass filter → gate → insert → EQ → compressor → delay → mute → fader

An aux may be configurable to take signal after the preamp, after EQ, after dynamics, or elsewhere. It may then be set pre-fader or post-fader. Some consoles also let you choose whether channel mute affects a pre-fader send.

This matters in practice:

• a monitor mix picked off before EQ may not receive corrective channel EQ;
• a post-EQ monitor send may change when FOH adjusts channel EQ;
• a pre-fader stream send may still receive dynamics or mute changes;
• a direct output may use a different source point from an aux;
• firmware, bus type, or show-file settings may alter available choices.

Never promise a performer that “pre-fader means FOH cannot affect it.” The shared preamp and selected processing may still be common to both paths. When isolation matters, document the split, gain ownership, processing boundary, and mute behavior explicitly.

Pre-fader listen is a different function

PFL commonly means pre-fader listen: an engineer monitors a channel before its fader through the console's solo or headphone bus. AFL commonly means after-fader listen. These monitoring functions help inspect signals but are not the same as configuring an aux send pre-fader or post-fader.

Build and test an aux routing plan

Start with named destinations. “Aux 1” describes a console bus, not who hears it or what the output feeds.

1. Name the destination. For example, MIX-01 Lead vocal IEM, FX-01 Vocal reverb, or REC-01 reference record.
2. List required sources. Include playback, talkback, ambience, click, cues, remote returns, and announcements where applicable.
3. Choose the control relationship. Decide whether main mix fader movements should affect each source in the destination.
4. Choose the source point. Confirm which channel processing, mute, and delay stages the destination should receive.
5. Assign the physical or digital output. Record port, connector, network channel, destination device, and owner.
6. Set output processing. Apply only the EQ, delay, dynamics, and protection required by that destination.
7. Test expected moves. Move a main fader, mute a channel, adjust relevant processing, and verify what the destination actually receives.
8. Save and label. Store the show file and label buses and outputs consistently with the rider.

Test behavior, not only signal presence

A line check proves that audio passes. It does not prove the correct pre/post relationship. For each important destination, verify:

• main channel fader up, down, and at the intended operating position;
• channel mute and DCA or mute-group behavior;
• preamp or trim ownership;
• channel EQ and dynamics changes relevant to the chosen pickoff;
• aux send and aux master operation;
• output processing, patch, and destination input;
• solo/PFL/AFL monitoring without interrupting the program;
• scene recall, safes, scope, and show-file behavior where used.

If a workflow depends on a console-specific option, record it in the show notes and confirm it after loading or converting a show file.

Aux-routing checklist

• Every bus has a destination name and owner.
• Required sources and exclusions are listed.
• Pre/post-fader behavior is chosen per source or bus as needed.
• Pickoff point, processing, and mute behavior are confirmed.
• Physical or network output patch matches the rider.
• Output level and receiving input are compatible.
• Talkback, cue, ambience, click, and confidential sources are routed intentionally.
• Fader, mute, processing, and recall tests passed at the destination.

Document sends in the rider

Connect the mix list to the input list and stage plot. Give each destination a stable ID:

For mixed configurations, record exceptions. A radio microphone sent to backstage may intentionally follow a different mute or fader rule from music channels. An announcement channel may feed the lobby even when it is not in the main mix. Specificity prevents an operator from “fixing” an intentional route.

In Techrider.live, name monitor destinations, connect them to performer positions and inputs, invite collaborators to edit the same rider, save the agreed routing notes, inspect history, and export a current PDF. Console show files remain equipment-specific; the Rider should preserve the human-readable intent needed to rebuild or verify them.

FAQ

What is the difference between pre fader and post fader aux?

A pre-fader aux send is independent of the channel's main mix fader. A post-fader aux send follows that fader. Both still have send-level and bus-master controls, and both may be affected by other stages such as preamp gain, processing, mute, or DCA behavior depending on the console.

Should monitor sends be pre fader or post fader?

Pre-fader is a common starting point when FOH fader moves should not change a performer's monitor balance. A dedicated monitor workflow or a special source may use different behavior. Confirm gain ownership, pickoff point, processing, mute logic, and output protection instead of treating “pre” as the entire monitor specification.

Why are effects sends post fader?

Post-fader routing lets the effect send follow changes to the dry channel in the main mix. Lowering a vocal therefore also lowers the amount sent to its reverb or delay. This often preserves the intended relationship, but the effect return and feedback path must still be routed and tested correctly.

Does pre fader mean pre EQ?

No. Pre-fader describes independence from the channel fader. The console may separately offer pickoff points before or after EQ, dynamics, insert, delay, or mute. Read the block diagram or routing screen for the actual bus and show-file configuration.

Should a recording feed be pre fader or post fader?

It depends on the deliverable. Isolated tracks normally should not follow FOH channel faders, while a simple two-track reference may intentionally follow a program mix. Define sources, processing, operator, monitoring, file format, and handoff first, then select and test the appropriate send point.

Make every mix destination-readable

Pre/post is useful only when it describes the behavior a destination needs. Create a Rider in Techrider.live to keep source IDs, monitor destinations, output assignments, and routing notes in one current handoff for the band and engineering team.