Directing AI Vocals in ACE Studio: Breath, Phoneme, Dynamic and the Advanced Parameters
The first thing that bothers you about an AI vocal usually isn't the sound quality. It's that the performance is off. The pitch is right, the words are right, and yet the breath lands in a strange place, the chorus doesn't lift, the ends of lines fall flat.
ACE Studio puts that part under your hands. The premise is that the AI supplies the voice and you direct the performance — so the parameter panel under the Clip Editor lets you move breaths, retime phonemes, shape intensity and adjust the voice itself.
Worth noting: this panel changed during 2026. Power, Soft, Breathy and Chest were folded into a single Dynamic curve. What follows describes the current V2 behaviour, checked against the official documentation on September 23, 2026.
Three places to intervene
The AI parameter panel sits at the bottom of the Clip Editor. On V2 models it splits into three tabs.
That order also works as a workflow. Handle how the words come out (Breath & Phoneme), then how the song rises and falls (Dynamic), then reach for the voice itself (Advanced) only where the first two weren't enough. The documentation is explicit that Dynamic is all you need for most songs. Starting with the four Advanced parameters is usually the long way round.
Breath & Phoneme: where it breathes, and how it articulates
A breath before a phrase is most of what makes a human vocal sound human. This tab covers that, plus the length of every consonant and vowel.
Add every breath, then delete the ones you don't want
Add all on the left of the lane drops breaths across the whole clip, placed where ACE Studio judges they belong — typically at the start of each phrase. Adding them all and removing the surplus is faster than placing them one at a time. Drag the left edge of a block to lengthen or shorten a breath.
Retime by moving the boundary
Notes appear split into phonemes. To change a duration you drag the boundary between two phonemes, not the phoneme itself — one side lengthens while its neighbour shrinks, so the note keeps its length.
The effect is predictable: a longer consonant gives the syllable a harder, more deliberate attack; a shorter one smooths the move into the next note.
- The boundary at the start of a note is fixed here. To change where a note begins, move or resize the note in the piano roll
- Phonemes you adjust turn blue and lock — they survive changes to notes, lyrics and even the AI voice
- Stretch or squeeze too far and the model may not follow the new duration precisely
Dynamic: intensity as a single curve
Dynamic governs how hard the voice is working, from soft and gentle to full and powerful. Push it up for choruses and dramatic moments, pull it down for verses and intimate passages.
This is what changed. On V2 models, Power, Soft, Breathy and Chest became this one curve. Instead of balancing four controls that each moved the needle a little, you draw intensity and ACE Studio works out the combination of vocal qualities behind it. Open an older project with edits to any of the four and the original lanes stay put, so nothing you already did is lost.
Leave it alone and Dynamic runs in Auto, inferring from melody, lyrics and the singer's style. Only the region you draw switches to Manual, which means you never have to draw the whole clip — fix the parts that bother you and leave the rest to the AI. Right-drag to erase and that region returns to Auto.
Two tools: a brush for freehand, and a line tool for clean crescendos and decrescendos. Some singers add a dedicated tab next to Dynamic, such as Rap or Opera.
Advanced: Air, Falsetto, Tension, Energy
Expand Advanced and four more parameters appear. Unlike Dynamic these aren't envelopes — they're the real synthesis values, 0 to 1, that get fed into the voice. Like AI pitch, they're generated from the singer's style, the melody, the lyrics and the pitch.
The important part is that they interact. The documentation pairs them directly: lower Tension if you want more falsetto, lower Tension again if you want a gentler sound out of Energy. When one parameter refuses to do what you expect, its partner is usually holding it back.
- AI-generated values are regenerated easily. Change notes, lyrics or pitch and the parameters for that section are rebuilt — even one changed lyric regenerates every parameter in that piece
- Anything you edit by hand becomes a user parameter and is left alone
- To lock the AI's own curve without changing its values, use the fixed brush. The eraser removes your edits and restores the generated values
- The docs repeat the same advice throughout: keep adjustments moderate. Extreme values produce unexpected performances
How far to take it
In practice the priority order is clear.
- Breaths first (Add all). The single biggest step toward sounding human, and the cheapest
- Then Dynamic. Lift the chorus, drop the quiet parts. The shape of the song is mostly decided here
- Then individual phonemes for the specific words that come out mushy, or too hard
- Advanced last, and only when you can say out loud what you want — "this one line needs more air", not "let's see what this does"
Which is the same thing as saying that opening with the Advanced parameters is inefficient. There's probably a reason the documentation keeps repeating that Dynamic is enough for most songs.
The official tutorial (with video demos)
ACE Studio publishes a tutorial that demonstrates these moves in short videos: converting a rough vocal to MIDI, adding a vocal run, editing breaths and phonemes, adjusting Dynamic and the expression controls, adding doubles and harmonies, and before-and-after comparisons — 11 videos across six chapters.
These are the kind of edits that are much easier to watch than to read about, so it's worth going through before you open the panel yourself.
Frequently asked questions
Q. What can I actually change after the AI sings?
A. On V2 models the AI parameter panel has three tabs: Breath & Phoneme, Dynamic and Advanced. You can place breaths and set their length, adjust the duration of individual phonemes, draw an intensity envelope across a phrase, and fine-tune Air, Falsetto, Tension and Energy. Some singers add an extra tab such as Rap or Opera.
Q. Where did Power, Soft, Breathy and Chest go?
A. On V2 models those four were merged into a single Dynamic curve. Rather than balancing four controls that each had a subtle effect, you draw one intensity curve and ACE Studio translates it into the right combination of vocal qualities. Projects that already contain edits to any of the four keep showing the original four lanes so existing work is preserved.
Q. Should I always use the Advanced parameters?
A. The official documentation says Dynamic is all you need for most songs. Air, Falsetto, Tension and Energy are for precise control over one specific vocal quality, and the docs advise keeping adjustments moderate, since extreme values can produce unexpected performances.
Q. Do my manual edits survive a lyric change?
A. Yes. Anything you edit by hand becomes a user parameter and is not regenerated when you change notes, lyrics or pitch. Phoneme durations you adjust turn blue and lock. Sections left on AI-generated values behave the opposite way: changing even a single lyric regenerates every parameter in that piece.
Summary
When an AI vocal sounds wrong, it's usually the performance rather than the pitch — and in ACE Studio the performance is editable.
- Breath & Phoneme: where it breathes and how long each sound lasts. Add all the breaths, then delete the ones you don't want
- Dynamic: intensity as one curve. Only what you draw goes Manual, so you don't have to draw everything
- Advanced: Air, Falsetto, Tension, Energy. Only with a specific goal, and gently
- Hand edits are kept; AI-generated sections get rebuilt the moment a lyric changes
You don't need to shape all of it. Adding breaths and lifting the chorus with Dynamic already changes the impression considerably. Pick one phrase and move it between Auto and Manual a few times — that's the whole idea in miniature.