Formant-shifting is a vocal production technique that can be heard all over the charts in 2025, from Billie Eilish to Travis Scott. Often confused with pitch-shifting, formant-shifting manipulates the timbre of a vocal while keeping its pitch intact.
Minimal Audio has announced the release of a new free formant-shifting plugin, fittingly – but perhaps a little unimaginatively – named Formant. Promising "real-time formant-shifting with musical, transparent results", Formant is a fast and simple tool for experimenting with different vocal characters in your productions.
A lightweight and stripped-back plugin with a basic XY pad interface, Formant is equipped with a built-in tilt EQ for brightening or darkening the tonal balance of the sound. Both this and the formant-shift can be controlled via the XY pad, and there's a Mix slider underneath for adjusting the balance between wet and dry signals.
The Minimal Audio team tell us they'd like to offer music creators an "accessible introduction" to their take on vocal processing with Formant, and are currently working on an advanced vocal production plugin named Evoke, due out later this year. This isn't the company's first free plugin release: they've previously given away Rift Filter Lite and Squash, an OTT-style compressor.
So how exactly does formant-shifting work? The technique is best explained in terms of the human voice. A typical vocal signal, like all signals with an inherent musical pitch, comprises a fundamental frequency - the root pitch - and mathematically-related harmonic overtones.
Regular pitch-shifting will transpose the fundamental and related harmonics up and/or down while maintaining their relationship, resulting in an obvious transposition of musical key. Need to tune a C vocal up to a C#? Then pitch-shift it up by one semitone - easy.
A vocal’s formants, on the other hand, are its inherent spectral frequencies - unrelated to pitch - created by that specific vocalist’s vocal tract, mouth shape and other resonant characteristics. It’s why, for example, one singer singing at C3 will sound completely different to another vocalist singing the exact same note. In broader terminology, we usually refer to this as ‘timbre’.
The process of formant shifting, then, allows you to manipulate these formants (and therefore timbre) while maintaining pitch. At subtler values, this can be used to gently shift a vocal performance’s timbre up or down, while more extreme changes are often perceived as ‘gender alteration’ - think extreme, chipmunk-style shifts or house-style deepening effects.
And though we’re using the human voice to illustrate, all audio signals contain unique formant frequencies, making formant processing a useful tool for altering the timbre of any instrument.
Minimal Audio Formant is available now for macOS and Windows in VST/VST3/AU/AAX formats. Find out more and download the plugin over at Minimal Audio's website.
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