After our last post covering parallel processing and the creative use of distortion, we feel the next topic to move into is the frenetic world of modulation effects.



Phase shift, chorus, flange and tremolo are the four basic modulation effects used today. For this post, we will leave out Tremolo as it deals with volume modulation, which is itself a useful phenomenon. We will instead focus on another type of signal modulation. In this case, modulation means that your source signal is being modified by another one, and with these three, an oscillator is the main source of “movement”. 

Besides the Phaser which does not use delay, but phase modulation, both the Chorus and Flange effect come from a modulation delay that is mixed back into the original signal. Resonance notches are slowly swept across the frequency bandwidth for flangers, phasers, and choruses to infer a sense of liquid like movement. Through this, each effect has its own signature sound that has similarities but stands apart in its physical approach and effect. 

We won’t get too deep into the overall physics here as more scientific resources are readily available, instead, we will focus on what aural transformations can occur from applying these effects and some tactics when handling them. They are the perfect go-to to bring life to static elements of an arrangement. From glistening cymbals that pulse pleasingly, to thick lively full bass tones or strings that surge and twinkle, this corner of the toolkit is essential and one of most satisfying to experiment with. 


Here is an example of a pedalboard using Flange, Chorus, and a Phaser along with Equalization and parallel processing.

Here is an example of a pedalboard using Flange, Chorus, and a Phaser along with Equalization and parallel processing. 


Here are a few of our favorite tips: 

  • Experiment with panning and offsetting the modulation time of elements in the mix being effected. A subtle sense of space and atmosphere can be dialed in when this is applied. Again don’t be afraid to break rules within the signal chain. Even reverb can come to life with a bit of phase shifting. 
  • The sense of “doubling” these effects apply is perfect for lead elements. From mono synths to guitars and horns or vocals, modulation effects can thicken and add needed presence to these tones.
  • Chorus can be applied to tame an off-key vocal without turning to autotune. This has been a trick since the 70’s and is a clever tactic to maintain the authentic quality of a vocal without it falling flat.
  • Remember that subtlety is an indication of sophistication. A little goes a long way and sometimes the best way to keep a mix uncluttered is to dial things back. An effect does not need to dominate a sound to improve it. Barely noticeable is usually enough.
  • As always, attention must be paid to the feedback, resonance, and frequency range of the effects settings to avoid damaged speakers, fatigued ears, and a muddied signal. We recommend applying a high pass filter to cut any excessive low end that may rob you of headroom along the way.
  • Clever shifting of the parameters of an effect over the course of a recording is a useful tactic to transform a sound’s characteristics. Knowing what to expect from these shifts is extremely important as you apply modulation effects to your signal. Things can slip into chaos if the wrong setting combinations are applied, so be aware of where things are heading as you work the controls. 


In closing, a fun exercise is to listen to where these effects are applied in your favorite recordings. Try to isolate each element and get a sense of where they are used. After some time invested in listening, it will become more obvious when they appear and how heavily they are applied. Familiarity is key to understanding when to implement these extremely useful effects and to what extent you wish to make them a significant part of your sound. But always remember that lifeless tones never have to stay static for long when Modulation Effects are available.