Flanger and phaser feature art

The difference between a phaser and a flanger has become a popular topic among budding recording artists working with audio frequencies. But this isn’t because of a contest between the two. One of the main reasons for this ongoing debate is that many enthusiasts in music don’t know what they are or how to use them. So, if you’re looking to learn about phasers and flangers and how to get the most out of them, the first thing you need to do is acquaint yourself with how they function.

In this article, we will go over the difference between a phaser and a flanger. We’ll also give you a few examples to make it easier to pick them out in the future.

What do phasers and flangers do?

Flangers and phasers both create notch effects in your audio, which reduces a narrow band or bands of frequencies. However, they achieve this effect in slightly different ways.


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How a phaser works

Phasers are one of the most versatile effects. Many musicians — especially guitarists — use phasers to create cuts in the high end of a signal and make automatic tonal changes. Phasers work by creating one or numerous notch filters and modulating the center frequency of the filter or filters.

When you use a phaser, the action splits the signal into two. It then uses an all-pass filter that modulates the phase on one of the signals. All-pass filters are used in circuit design to achieve a range of time-shift functions or frequency-dependent time alignment. The two signals are then mixed together again and the out-of-phase frequencies get canceled out. This creates the notches characteristic to the phaser effect.

Examples of phasers include Jimi Hendrix’s “Little Wing” and David Gilmour’s guitar in Pink Floyd’s “Shine on You Crazy Diamond.” If you listen carefully, you can hear the sweetened, subtle tone and organic sounds that a phaser produces over the more metallic sound of the flanger. One of the best ways to use the phaser is to give more life and character to your tone. 

How a flanger works

A flanger uses the same process but adds a delay to one of the signals. This delay is only a fraction of a second. This creates an effect known as a comb filter. When two noises or sounds from the same source reach your ears at separate intervals, the complex patterns of sound pressure variations overlap and interfere with each other. The filter has several apexes and channels of amplitude — known as “teeth” — across the frequency range.

When the delay time is changed — generally with an LFO — these teeth move to create the swirling or swooshing effect we recognize as phasers and flangers. Keep in mind that professionals advise beginners to avoid flangers unless you know what you’re doing. But when you do reach that professional level, you can create really cool delay effects. 

A flanger creates an identical quantity of notches during the entire audio item, taking the original signal and affixing it back onto itself without letting up. A flanger doubles your input signal and plays both back together. It works by combining two identical audio signals, with one of the signals playing at a somewhat gradual speed. The video below is a good example of a flanger.

Classic rock offers perfect examples using the flanger effect. A perfect example is the breakdown in the middle of “Listen to the Music” by The Doobie Brothers. Another famous example is The Beatles’ “Tomorrow Never Knows.” When you listen to these examples, you can hear that flanging is essentially closer to a chorus effect than it is to a delay effect. Extending the delay in a flanger will give you a chorus effect.

One of the best ways to start using a flanger is by downloading a flanger plugin. Once you test out the effect, then you can buy a flanger and hear for yourself what it sounds like in action. 

How flangers and phasers process audio

Phasers process audio using all-pass filters to bring together peak levels and notch loudness into an audio signal’s frequency spectrum. Phasers allow you to control the peak levels and notches used and the frequencies they’re modifying. Just remember, phasers come with an LFO that regulates the center frequencies because, on its own, the level of music loudness is far from dramatic.

On the other hand, the flanger duplicates the received audio signal and delays the duplicate to create peak levels and notches in the audio signal’s frequency spectrum. This means is that a flanger will create an obvious pitch as the comb filter’s peak levels shift up and down the frequency spectrum. This creates a linear harmony that you don’t get with phaser peak levels. 

Developing an ear for the flanger and phaser

Not many people have an ear capable of discerning the difference between flangers and phasers unless they grew up playing specific instruments, like the guitar, or had an education in music. Those who studied music learn to understand the relationships and sounds of chords, melodies and instruments. But if you listen to popular songs, you can get a feel for the ones that use the phaser and flanger differently. For example, some songs use a phaser with a clean tone. Others songs use it with a drive tone, like “Paranoid Android” by Radiohead or “Shattered” by The Rolling Stones. Once you develop an ear for songs that use phasers and flangers, you will eventually be able to pick them out. The best way to tell the two apart is by playing around with both until you develop a good ear for their differences in sound and effect. 

Flanger vs. phaser: Final thoughts

So here’s what you should know in a nutshell: Phasers are frequency-based and works by altering phase, while flangers are time-based and work on a time delay. Phasers filter signals by creating a series of peak levels and normally divide the sound into two tracks. Flangers double your input signal and play both back together. Phasers work by creating one or more notch filters and modulating the center frequency of the filter or filters. A flanger takes the original signal and loops it indefinitely. If you lengthen the delay in a flanger, you have a chorus effect.

The easiest way to tell the difference between the two is to know how they sound. A flanger has an added metallic sound while a phaser’s sound is more organic. Often, people describe flangers as sounding like jet engines. Phasers are commonly compared to swirling and swooshing effects. They’re both available in analog and digital versions with similar sounds. 

Recording artists have learned these effects can destroy your mixes if you use them incorrectly. But once you play around and experiment, they can really add cool effects to your music and improve your recordings. Once your ears like what they’re hearing, you’re ready to transform your mixes into the next era of stand-out hits.