Phasing, Flanging, and Chorus 101: Recognizing Short-Delay Time Domain Effects

Phasing, flanging, and chorus belong to a specific family of time-domain effects that rely on extremely short delay times.

Unlike echo or delay effects that produce clearly audible repeats, these processes operate within a range where the delay is perceived alongside the original signal, creating movement, depth, and tonal variation rather than repetition.

At the core of these effects is a shared principle:

Very short delays combined with modulation create complex phase interactions between the original signal and its delayed copy.

From subtle tonal shifts to dramatic resonant sweeps, these effects shape sound by exploiting how waveforms interact with themselves over time.

Time Domain Effects and Short Delay Ranges

Time domain effects manipulate sound by delaying it in time. In the case of phasing, flanging, and chorus, the delay times are the shortest of all time-based effects, typically ranging between

  • 1 millisecond
  • 30 milliseconds

Within this narrow window, the delayed signal does not register as a discrete echo. Instead, it interacts directly with the source signal, producing phase-related phenomena that change continuously when modulation is applied.

Phasing: Modulated Micro-Delays and Phase Interaction

Delay Time Range for Phasing

Phasing operates at the shortest delay times of all:

  • Typically between 1 and 3 milliseconds
  • Sometimes extending down to 0 milliseconds

At these values, the delayed signal aligns closely with the original waveform. When both signals are heard together, their interaction creates an effect known as phasing.

How Phasing Works

Phasing is created by modulating the delay time—continuously varying it using a low-frequency modulation source. This modulation causes the delayed signal to shift in and out of alignment with the original signal.

Because these delay times fall within the duration of individual waveform harmonics, the interaction produces:

  • Complex phase differences
  • Alternating cancellation and summing
  • Subtle tonal movement rather than audible echoes

These are more phase-related effects than straightforward repeats.

Comb Filtering and Phase Cancellation

The interaction between the source signal and its delayed copy results in a phenomenon often referred to as comb filtering. This occurs when certain frequencies cancel out while others reinforce each other, creating a frequency response that resembles the teeth of a comb.

Audibly, this produces:

  • Hollow or swirling tonal shifts
  • Frequency notches that move over time
  • A sense of motion within the sound

The Role of Feedback in Phasing

Adding a small amount of feedback routes part of the processed signal back into the input of the effect. This creates:

  • Additional resonances
  • More pronounced phase interactions
  • Enhanced depth and intensity

Even modest feedback levels can significantly strengthen the phasing character without pushing the effect into more extreme territory.

Typical Phasing Settings

Common parameter ranges for a phasing effect include

  • Delay time: Modulated between 0 and 3 milliseconds
  • Feedback: Low
  • Modulation speed: Slow
  • Modulation width: Wide

These settings emphasize smooth, evolving phase movement while maintaining subtlety.

Flanging: Intensified Phasing with Resonant Feedback

Flanging is closely related to phasing but takes the concept further by increasing both delay time and feedback, resulting in a more dramatic and pronounced effect.

Delay Time Range for Flanging

Flanging typically observes delay times between:

  • 3 milliseconds
  • 13 milliseconds

While still short enough to avoid audible repeats, these longer delays introduce deeper and more noticeable phase interactions.

What Makes Flanging More Extreme

The defining characteristic of flanging is the use of greater amounts of feedback. This feedback creates:

  • Strong resonant peaks
  • Sweeping harmonic emphasis
  • Intense tonal movement across the frequency spectrum

Flanging utilizes greater amounts of feedback to create dramatic resonance effects.

As the delay time is modulated, these resonances move, producing the classic jet-like or metallic sweeping sound associated with flanging.

Typical Flanging Settings

Standard flanging configurations include:

  • Delay time: Modulated between 3 and 13 milliseconds
  • Feedback: High
  • Modulation speed: Medium
  • Modulation width: Medium

These settings balance movement and intensity, allowing the resonant sweeps to remain controlled yet expressive.

Chorus: Creating Thickness Through Time and Pitch Variation

At longer short-delay times, the chorus effect emerges. While still part of the same time domain family, chorus produces a distinctly different result.

Delay Time Range for Chorus

Chorus effects generally use delay times between:

  • 13 milliseconds
  • 30 milliseconds

At this range, the delay no longer behaves primarily as a phase interaction tool. Instead, it creates the impression of multiple sound sources.

How Chorus Works

Chorus blends the dry signal and the effected signal at equal levels. The delayed signal is subtly modulated in time—and often perceived as slightly shifted in pitch—creating natural variation.

The goal is simple:

To create the effect of two or more instruments playing together.

This illusion is achieved through:

  • Small time differences
  • Subtle pitch differences
  • Continuous modulation

Unlike flanging or phasing, chorus avoids strong resonances or cancellations.

Chorus Compared to Vibrato

Chorus is similar to vibrato, but with one critical distinction:

  • Vibrato: Fully wet signal (pitch modulation only)
  • Chorus: Equal blend of dry and effected signal

This blend preserves clarity while adding width and richness.

Typical Chorus Settings

Common chorus parameter values include:

  • Delay time: Modulated between 13 and 30 milliseconds
  • Feedback: Little or none
  • Modulation speed: Medium
  • Modulation width: Narrow

These settings maintain subtlety, preventing the effect from becoming exaggerated or unnatural.

Comparing Phasing, Flanging, and Chorus

While all three effects share a foundation in short delay modulation, their sonic identities differ based on delay time, feedback, and modulation behavior.

Key Differences at a Glance

  • Phasing
    • Shortest delay times
    • Minimal feedback
    • Emphasis on phase cancellation and summing
  • Flanging
    • Slightly longer delays
    • Heavy feedback
    • Strong resonant sweeps and dramatic movement
  • Chorus
    • Longest short delays
    • Little or no feedback
    • Perception of multiple instruments playing together

Each effect occupies a unique position along the delay-time spectrum, shaping sound through increasingly perceptible temporal separation.

Modulation as the Driving Force

Across all three effects, modulation is the mechanism that brings movement to static delays. By continuously varying delay time:

  • Phase relationships shift
  • Frequency interactions evolve
  • Sound gains motion and depth

Whether subtle or extreme, modulation transforms short delays into expressive tools for shaping tone and space.

Phasing, flanging, and chorus do not rely on repetition—but on interaction.

By working within the smallest time windows, these effects demonstrate how even milliseconds can dramatically influence how sound is perceived.