[Feature Request] Pitch / Formant Effect: "Ioio" Vocal Filter (Fractal Style)

Quad Cortex Feature Requests
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Hi Quad Cortex Community & Neural DSP Team,
I’d like to submit a feature request for a dedicated Pitch Formant effect that replicates the popular “Ioio” vocal filter sound found on Fractal Audio devices (Axe-Fx, FM3, FM9).
Overview
The “Ioio” effect is a staple for expressive lead playing, synth-like tones, and vocal guitar lines (famously used by players like Guthrie Govan and Steve Vai). It combines pitch manipulation with human vowel formant filters, dynamically shifting between the “I” and “O” sound shapes.
Suggested Controls / Parameters

  • Type/Mode: Vowel / Formant Pitch
  • Start & End Vowels: Allow selection between vowels (specifically tuned for I to O)
  • Control Source: Envelope Follower (picks dynamics), Pitch Tracking, or Expression Pedal / MIDI
  • Resonance / Q: Adjust how pronounced the vocal formant peaks sound
  • Shift Range: Pitch sweep range linked to the formant transition
  • Mix & Sensitivity: Standard wet/dry blend and input envelope response threshold

Why this would be a great addition to CorOS
While the Quad Cortex already has great pitch and wah models, having a dedicated dynamic vocal formant algorithm would open up incredible synth and talk-box style textures without needing extra external hardware.
If you’d love to see this added to CorOS, please vote on this thread!
Thanks for considering this, Neural team!

2

There is a very similar request…

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Thanks for pointing that out!
There’s actually a slight difference: a standard Talk Box sim mimics the tube filter sound, while the “Ioio” is a vocal formant filter (shifting from “I” to “O”) tied to picking dynamics or pitch tracking.
That said, they both belong to the same vocal/formant effect category that the Quad Cortex is currently missing! If Neural develops a dedicated Formant block, it could easily cover both Talk Box and Ioio sounds.
I’ll head over and upvote that thread too—hopefully we get these vocal effects on CorOS soon!