What is a flanger?

A flanger is an audio effect that creates a swirling, whooshing, or jet-plane-like sound. It works by mixing two identical signals together, with one signal delayed by a small, varying amount (typically less than 20 milliseconds). This delay creates a comb filtering effect, resulting in peaks and dips in the frequency spectrum that shift over time.

Here's a breakdown of key aspects:

• How it works: A flanger operates on the principle of constructive and destructive interference. The delayed signal combines with the original, causing some frequencies to be reinforced (constructive interference) and others to be cancelled out (destructive interference). The constantly changing delay time causes these cancellations and reinforcements to sweep across the frequency spectrum, producing the characteristic swirling sound.

• Controls: Common flanger controls include:

  • Delay Time: This controls the base delay time of the delayed signal. Shorter delay times produce a more subtle effect, while longer delay times create a more pronounced and dramatic flange.
  • Depth/Width: This determines the range of the delay time modulation. A wider depth creates a more extreme sweeping effect.
  • Rate/Speed: This controls the speed at which the delay time is modulated. Faster rates create a faster, more intense flange, while slower rates produce a more subtle, gentle sweep.
  • Feedback/Regeneration: This feeds a portion of the flanged signal back into the delay line, emphasizing the peaks and dips in the frequency spectrum and creating a more resonant and pronounced flanging effect. Higher feedback settings can lead to a more intense and pronounced swirling effect.
  • Manual: Some flangers include a manual control that allows the user to manually sweep the delay time for more precise control over the flange effect.
  • Mix/Blend/Level: This controls the balance between the original signal and the flanged signal. A higher mix level will result in a more prominent flanging effect, while a lower mix level will create a more subtle effect.
  • LFO (Low-Frequency Oscillator): Modulates the delay time. The LFO can be set to different waveforms such as sine, triangle or square.

• Applications: Flangers are used in a variety of genres and on various instruments, including:

  • Guitars: Creating a swirling, psychedelic effect.
  • Vocals: Adding a unique texture and depth.
  • Drums: Making drum sounds more interesting and energetic.
  • Synthesizers: Enhancing the sonic complexity and adding movement.

• History: The flanger effect originated in the early days of tape recording, when engineers discovered that by manually slowing down one of two synchronized tape machines, they could create a similar effect to what we now know as flanging. This "manual flanging" technique was later replicated electronically using analog circuits and then digitally with plugins.

• Types: There are different types of flangers, including:

  • Tape Flangers: Emulate the sound of early tape flanging techniques.
  • Analog Flangers: Use analog circuitry to create the flanging effect.
  • Digital Flangers: Use digital signal processing (DSP) to create the flanging effect.
  • Through-Zero Flangers: These create a unique effect where the delay time crosses zero, producing a distinct "swooshing" or "warping" sound.