Pre Fader vs Post Fader (Use Cases, Diagrams & More)

• When should you use pre fader vs post fader and vice versa?
• This guide explains the difference between pre and post fader.
• Practical applications diagrams, and use-cases for each.
• Also, check out our article on Upward vs Downward Compression

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Pre FAder vs Post Fader

Pre or post-fader refers to signal sends (to an auxiliary or bus channel) either in your DAW or on a physical mixing console, more specifically where you send them from.

In audio signal processing, pre fader and post-fader refers to audio signal sends to an auxiliary or bus channel either in your DAW or on a physical mixing console. Here’s a quick recap:

• Pre-Fader: Processing takes place before the audio signal reaches the fader on a mixing console or within a DAW.
• Post-Fader: Processing occurs after the audio signal passes through the fader or volume control within a DAW or mixing console.

An easy way to understand them is to imagine your signal flow in a linear format and where the channel fader lies.

A pre fader send simply routes a copy of your track before the channel fader, whereas a post fader send will do this after your channel fader.

But what difference does it make?

In the context of mixing, using a pre fader sent is preferred over post fader, as it ensures the signal remains independent of the channel fader.

So, you are free to raise or lower the fader without influencing the level that is being sent to the auxiliary track.

The concept of pre vs post fader routing is fairly simple, but one that every music producer should take a moment to understand. Doing so can improve your workflow both in terms of speed and quality of audio.

When To Use Pre Fader OVer Post Fader?

Pre Fader Use Case #1: Effect Tracks

One of the main advantages of using pre fader sends is it allows you to use an auxiliary or bus track exclusively as an effect track like reverb.

For instance, let’s assume you’ve found a sweet spot on your guitar reverb.

If the signal is sent post fader, any tweaks made to the guitar channel fader affect how the reverb sounds. This isn’t great for your workflow and can potentially lead to a perpetual cycle of adjustments.

Conversely, you can insert a reverb plugin onto the track you want to affect. Using an auxiliary track just for your effect means you can route multiple tracks into one effect, using one plugin for the whole process.

However, it’s important to note that using this method is only CPU-efficient when you route multiple tracks into one effect.

Using multiple plugins with effects on each track of your project will significantly eat into your computer’s resources.

A great way of improving your mixing workflow is to set up a template, typically equipped with two reverb auxiliaries (long and short) and two delay auxiliaries (long and short).

This method simplifies the routing of your tracks and gives independent control over the effect. You are now free to lower or raise your channel faders without changing the effect.

Once you set up these templates, set the ‘dry’ parameter on your reverb and delay to zero and the ‘wet’ parameter to its maximum value.

This setup ensures that the auxiliary track will only produce the affected sound, so you can easily fine-tune the single to taste.

It also ensures you have a dry, unaffected track that can be blended with your channel faders to attain the desired mix.

Next, insert an EQ plugin after your reverb and use a high pass filter to resolve issues related to muddiness that reverbs typically introduce.

Doing so also allows you to aggressively EQ the reverb without affecting the original signal.

In the example below, you can see a vocal track being routed to a long reverb and long delay track.

The vocals have independent level and the faders on the effect tracks are set to different levels. They’ll not be affected by changes in the vocal fader.

The effects are set to 100% wet, meaning the only thing we hear on these tracks is the effect, and a HPF has been applied with the EQ plugin.

The level of signal being sent to the effect tracks can also be adjusted.

P.S. – Explore our article on EQ Before or After Reverb (3 Use Cases).

Pre Fader Use Case #2: Parallel Compression

Apart from effect tracks, pre fader sends also find utility in applying parallel compression to drums tracks. In parallel compression, the original track is blended with a heavily compressed track.

In this context you’d want to hear all your drum mics while routing each track to a dedicated compression track to be heavily compressed.

Sending the signal pre fader ensures you can simultaneously hear both dry and wet tracks. If you want more prominent cymbals in the dry mix than the auxiliary track or vice versa.

So, it only takes a few simple tweaks to create two distinct drum mixes.

Pre Fader Use Case #3: on a Mixing Console

The core concept of pre fader sends can be utilized on a mixing console as well as in the box (DAW).

Like the first and second use cases, pre fader sends can be used to create auxiliary tracks to be compressed or sent to a piece of outboard gear.

Additionally, a pre fader send is advantageous when creating mixes for a performer to hear in their headphones.

For example, when tracking drums, drummers generally want to hear the backing or guide track, as well as the click track to stay in time.

However, you’ll be monitoring other things in the control room, such as the microphones, drummer’s performance, and overall feel.

By sending both tracks to the headphones pre fader, you can create a separate mix for the drummer and in the control room.

Since you’ve sent your signal pre fader, both you and the drummer have their own mix. This allows you to adjust the click, drums, or guide track via the control room desk faders without changing what they are hearing.

When To Use Post Fader Over Pre Fader?

Post Fader Use Case #1: Bussing

In audio production, one of the commonly used applications of post-fader sends is in bussing – where multiple audio tracks managed collectively.

This is because routing signals through post-fader gives you centralized control via a single master fader.

Let’s assume you are working with a guitar-heavy track – double-tracked guitars and a lead line. You’re happy with the overall levels but notice that they sound too loud during the chorus.

Here, you can route the output of all the guitar tracks to an auxiliary track, sending the signal after the channel faders.

With a bit of simple automation on the auxiliary track, you can adjust their collective level with one fader instead of three.

In the image below, you can observe how the output of each track is routed to the Guitar Bus. This means that the levels of each guitar track can be controlled by the bus track in yellow.

In this example the output of each track is routed to the Guitar Bus.

This means that the levels of each guitar track can be controlled by the bus track in yellow.

Note: There is a difference between routing your channel output to an auxiliary and using a send. A send can be set to post fader but will route a copy of the signal to the auxiliary, so you will hear your original tracks and volume will be independent from the auxiliary.

In the example below, the guitar tracks are sent post fader, so the bus fader in yellow will control a copy of the signal, rather than the original.

BEfore You Go

As you can see, the pre fader vs post fader approaches are distinct, and both have their advantages.

Employing a pre fader send gives you an extra level of depth when it comes to mixing effects and can create some really interesting sounds which often will add another dimension to your mix.

That’s not to say post fader sends aren’t useful, as they are a great way to control the levels of a group of instruments.

Here are some related articles that may help you achieve mix depth:

• How to Set Mixing Levels (+ Volume Balancing Cheat Sheet)
• 7 Different Types of EQs and When To Use Each
• Where Should a Compressor Go in the Chain?