Understanding Faders In Audio Mixing: What Are Faders? How Are They Used?

Audio mixing is a complex and fascinating process that requires both technical knowledge and artistic intuition. 

Whether you’re working in a professional studio, creating your own music at home, or managing the sound for a live event, the fader is one of the most fundamental tools you have at your disposal.

What are faders on a mixer?

Faders on a mixer, also known as slide potentiometers, are control devices that allow you to adjust the volume or level of intensity of different audio signals.

Found on every mixing console and digital audio workstation (DAW), faders play a crucial role in shaping the sound of a mix. They allow you to control and balance the volume levels of individual tracks, groups of tracks, or the mix as a whole. 

But faders aren’t just simple volume controls—they’re also used to create dynamics, apply effects, and more.

They are essential to audio mixing, providing precision control over sound levels and dynamics. However, understanding their full potential requires more than just knowing how to move a slider up and down.

What Are Faders Used For?

Faders on a mixer serve several purposes in both live and studio audio production:

1. Volume Control: Faders’ primary function is to control the volume of individual tracks or channels. By adjusting these faders, you can ensure that no single sound source overpowers the others and that all elements of the mix can be heard clearly.
2. Balancing the Mix: Faders allow you to balance the levels of various sound sources in a mix. This is crucial for creating a well-balanced mix where all elements can be heard clearly and contribute effectively to the overall sound.
3. Creating Dynamics: Faders can be used to create dynamics within a song or performance by adjusting the volume of different elements over time. For example, you might lower the volume of a vocal track during a guitar solo to make the solo stand out more.
4. Subgroup Mixing: Subgroup faders allow you to adjust the volume of a group of channels collectively. This can be very useful when dealing with multiple mics on a single source (like a drum kit) or when you want to adjust the levels of all backing vocals at once, for instance.
5. Auxiliary Sends: Auxiliary send faders allow you to control how much of a channel’s signal is sent to an auxiliary output. This is useful for applying effects to a channel or for creating monitor mixes in live sound situations.
6. Fade In/Fade Out: Faders can be used to smoothly increase or decrease the volume of a track at the beginning or end of a song, a technique known as a fade-in or fade-out.
7. Master Volume Control: The master fader controls the overall volume of the final mix. This allows you to easily adjust the overall level of the mix without affecting the balance between individual tracks.

Faders play a crucial role in the process of shaping and crafting the sound in both live and recorded audio. The ability to control and manipulate these various elements is what makes a good mix engineer.

Types Of Faders On A Mixer

Different types of faders can be found on a mixing console or digital audio workstation (DAW). Here are the main types:

1. Channel Faders: These faders control the volume of individual audio tracks or channels. They are the most common type of faders and can be found on virtually every mixer.
2. Master Fader: This fader controls the overall volume of the mix. It allows you to adjust the volume of the final mix without altering the balance between the individual channels.
3. Subgroup Faders: These faders collectively control the volume of a group of channels. They are useful when you want to adjust the level of several channels at once, such as when you have multiple microphones recording a single instrument or multiple backing vocals.
4. Auxiliary Send Faders: These faders control the amount of an audio signal sent to an auxiliary output. This can be used to send signals to external effects processors or monitor speakers.
5. VCA Faders: VCA (Voltage Controlled Amplifier) faders control the volume of multiple channels at once without combining their signals into a subgroup. This means you can control the level of several channels, each with its own EQ and pan settings, with a single fader.
6. Motorized Faders: These faders can move automatically to preset positions. This is particularly useful in digital audio workstations or high-end digital mixers, where the fader positions can be saved and recalled as part of different mix scenes or automation data.
7. Linear Faders: The most common type of fader moves up and down in a straight line. They provide a visual representation of the volume level.
8. Rotary Faders: Also known as rotary potentiometers or knobs, these faders are turned clockwise or counter-clockwise to increase or decrease volume. They are common on smaller mixers and some digital audio interfaces where space is limited.

Each type of fader has its specific applications and uses, and many mixers will include several different kinds of faders. The choice between them often comes down to the audio project’s specific requirements and the sound engineer’s preferences.

Fader Quick Reference Guide

Fader Type	Primary Function	Common Use Case
Channel Fader	Controls individual track volume	Mixing vocals, instruments, or effects on a console
Master Fader	Adjusts overall mix level	Final mix balancing and output control
Subgroup Fader	Controls the volume of multiple grouped channels	Managing drum kits, backing vocals, or instrument sections
Auxiliary Send Fader	Sends a portion of a track’s signal to external sources	Applying reverb, delay, or creating monitor mixes
VCA Fader	Controls multiple faders without affecting individual settings	Live sound mixing, adjusting grouped instruments efficiently
Motorized Fader	Moves automatically to match automation data	Digital mixers, DAWs, studio automation
Linear Fader	A straight-line sliding control for volume adjustment	Most analog and digital mixing consoles
Rotary Fader	A knob-style fader that turns instead of sliding	Space-limited mixers, digital interfaces, and compact consoles

What Is A Motorized Fader?

A motorized fader is a type of fader found on some mixing consoles and digital audio workstations (DAWs) that can move automatically to different positions.

“Flying faders” is another term for motorized faders

The motorized fader is designed to provide automatic control over the volume level of an audio signal, and it can be programmed to move to specific positions at specific times.

This is particularly useful in a few different situations:

1. Mix Automation: In a DAW or digital mixer, you can automate the faders’ movements over a song or track. For instance, you might program the faders to lower the volume of a vocal track during a guitar solo or to increase the volume of a track for a fade-in gradually. The motorized faders will follow the automation data you’ve set, moving up and down as needed.
2. Recall of Mix Settings: If you’re working on a mix and need to take a break, or if you’re working in a studio where multiple people use the mixer, motorized faders can be a huge help. You can save the positions of the faders as part of a mix “scene” or “snapshot” and then recall that scene later. The motorized faders will automatically move to the positions they were in when you saved the scene, allowing you to pick up exactly where you left off.
3. Control Surface Integration: If you’re using a control surface (a hardware device designed to provide tactile control over a DAW), it may have motorized faders. When you switch between different tracks or projects in your DAW, the faders on the control surface can automatically move to match the levels of the tracks in the software.
4. Remote Control: In some cases, a DAW or other software can remotely control motorized faders. This allows the engineer to control the faders from a different location, which can be useful in large studios or live sound situations.

Motorized faders provide a visual and physical representation of the mix settings or automation data, which many audio engineers find helpful for making precise adjustments to the mix. 

Due to their automated and motorized nature, flying faders tend to be more expensive than regular, manual faders, so they’re typically found on higher-end mixers and control surfaces. 

What Are Channel Faders?

Channel faders are controls found on a mixing console or digital audio workstation (DAW) that adjust the volume or intensity of individual audio tracks or channels. Each input channel in a mixer will typically have its own dedicated channel fader.

These faders allow the audio engineer to balance the relative volumes of different sound sources. In a music mix, for instance, you might have separate channels for vocals, guitar, bass, drums, and other instruments. 

The channel faders would allow you to adjust the volume of each of these elements independently, helping to ensure that no single instrument or voice overpowers the others and that all elements can be heard clearly in the mix.

Channel faders can also be used to create dynamics within a song or performance by adjusting the volume of different elements over time. 

For example, you might reduce the volume of a vocal track during a guitar solo to let the solo stand out or increase the volume of a quiet instrument during a particular section of a song.

In some advanced mixing consoles and DAWs, channel faders may also control the amount of a channel’s signal sent to auxiliary outputs (for effects processing or monitor mixes), though this is typically controlled by separate “aux send” controls.

Channel faders are a fundamental tool in audio production, vitally shaping the sound of a mix.

What Is The Master Fader?

The master fader on a mixing console or digital audio workstation (DAW) adjusts the overall volume of the mix. 

Unlike channel faders, which control the volume of individual tracks or channels, the master fader controls the final output level of all tracks combined.

Here’s a more detailed explanation of its role:

1. Overall Volume Control: The master fader controls the overall volume of the mix. This allows the audio engineer to adjust the overall loudness without altering the balance between individual tracks that have been set with the channel faders.
2. Prevent Distortion: The master fader is also important for maintaining the audio signal’s integrity. If the combined levels of all the tracks exceed the maximum level that the mixer or audio interface can handle (known as “clipping”), distortion can occur. By adjusting the master fader, you can ensure that the overall level of the mix doesn’t exceed this maximum level.
3. Final Adjustments: In the final stages of mixing or mastering a track, the master fader can be used to make minor adjustments to the overall volume level. This can be useful for ensuring that the track is at an appropriate volume level compared to other tracks.

The master fader is typically located on the far right of the mixer or DAW interface, separate from the channel faders. When exporting stems or individual tracks, adjustments to the master fader do not affect the individual track levels—they only affect the final stereo mixdown.

What Are Subgroup Faders?

Subgroup faders are controls on a mixing console or digital audio workstation (DAW) that allow you to collectively control the volume of a group of channels. They’re helpful when you want to adjust the level of several channels at once.

For example, you might have multiple microphones set up to record a drum kit, each capturing a different part of the kit (snare, kick, hi-hat, toms, cymbals, etc.). 

Instead of adjusting each channel’s fader individually every time you want to change the overall volume of the drums, you could route all of these channels to a subgroup. Then, by adjusting the subgroup fader, you could control the overall volume of the drums with a single fader.

Similarly, if you have several backing vocal tracks that you want to treat as a single unit, you could route them all to a subgroup. This would allow you to adjust the overall level of the backing vocals, apply effects to all of them at once, or mute them all at once, among other things.

In essence, subgroup faders give you more control over your mix by allowing you to manage groups of related tracks as a single unit. This can make the mixing process more efficient and help you create a more balanced and cohesive sound.

Advanced Techniques for Using Faders

1. Parallel Compression with Faders
   • Parallel compression, also known as New York compression, involves blending a heavily compressed version of a signal with the dry, uncompressed signal. Engineers use faders to control this balance, allowing for increased presence and sustain without squashing the dynamics.
   • This technique is widely used on drums, bass, and vocals to maintain energy and clarity while avoiding the dullness that over-compression can cause.
   • To execute this effectively, use an auxiliary send for the compressed signal and blend it back into the mix using a fader to fine-tune the level.
2. Creating Depth with Faders
   • Depth in a mix isn’t just about volume but also spatial positioning. Engineers use faders to adjust the relative loudness of foreground and background elements to create a sense of three-dimensionality.
   • Pairing fader movements with reverb and delay adjustments helps place sounds closer or further away.
   • A common trick is to subtly automate faders so that supporting instruments dip slightly when the lead elements come in, preventing competition for attention.
3. Fader Automation for Precision Mixing
   • Instead of relying solely on static levels, professional mixes often use automation to adjust faders dynamically throughout a track.
   • Automation allows for subtle volume rides that prevent lifeless or mechanical-sounding mixes.
   • Examples include lifting vocal faders slightly during a chorus, dropping guitar faders during verses, or using automation to create fade-ins and fade-outs for cinematic effect.
4. Faders and EQ Interplay
   • Lowering the volume of an instrument using faders can sometimes make it less clear in the mix. To counteract this, professionals tweak EQ settings alongside fader adjustments.
   • Example: If a guitar fader is lowered, boosting 3-5 kHz can help retain presence.
   • A/B testing fader and EQ adjustments ensures that changes improve clarity without removing essential tonal characteristics.
5. Pre-Fader vs. Post-Fader Effects
   • Effects like reverb and delay behave differently depending on whether they receive their input signal pre- or post-fader.
   • Pre-fader sends allow the effect signal to remain consistent even if the main fader is lowered—useful for creating lush, ambient effects.
   • Post-fader sends adjust the effect intensity in tandem with fader movements, leading to a more natural and organic response.
   • This technique is particularly important when using delay trails that need to fade naturally as a vocal line decreases in volume.
6. Fader Law and Tapering
   • Not all faders respond the same way. Fader tapering defines how quickly a fader increases or decreases volume relative to its position.
   • Most professional mixers use logarithmic fader tapers, meaning small movements at the top result in larger changes than those at the bottom.
   • Understanding these response curves is essential for making precision gain adjustments in critical mixing scenarios.
7. Grouping and VCA Faders
   • Engineers group similar elements using VCA (Voltage Controlled Amplifier) faders or subgroups to control multiple channels simultaneously.
   • Instead of adjusting each drum individually, a single drum bus fader can be used to balance the overall drum sound.
   • VCA faders are particularly useful in live mixing situations, allowing engineers to make quick adjustments without disturbing individual track settings.
8. Faders and Headroom Management
   • Maintaining headroom is crucial for clean, distortion-free mixes. Pushing individual faders too high can cause digital clipping or overloading in analog systems.
   • A common best practice is to set individual tracks so that the master fader stays around -6 dB, leaving enough room for mastering engineers to work with.
   • If a mix lacks power, instead of boosting faders, lower other elements to create natural headroom while preserving dynamic range.

Key Takeaways

• Faders do more than adjust the volume; they shape the dynamics and feel of a mix.
• Professional engineers use faders for real-time mixing, automation, and dynamic control.
• Watching expert tutorials and applying advanced techniques like parallel compression can significantly improve mixing skills.
• Experimenting with fader positions helps create depth and clarity in a mix.
• Advanced techniques like pre-fader vs. post-fader sends, automation, VCA grouping, and fader tapering can elevate your audio mixing.
• Managing headroom and signal integrity is essential for achieving a professional mix.

Conclusion

Understanding the different types of faders and their roles in audio mixing is fundamental for anyone involved in audio production, whether you’re a professional sound engineer, an aspiring producer, or a musician recording your work. 

Faders are more than simple volume controls – they are essential tools for balancing the mix, creating dynamics, applying effects, and shaping the overall sound of a track or performance.

From the individual control of channel faders, the collective adjustments of subgroup faders, the overall control provided by the master fader, to the automated precision of motorized or “flying” faders, each type of fader has its unique function and place in the mixing process.

While technical knowledge is good to know, don’t forget that the best mixes also require a good ear, creativity, and a feel for the music. With practice and experience, you can learn to use faders effectively to bring your artistic vision to life. Happy mixing!