
Free 3-day demo · VST3 · AU · macOS & Windows · every feature unlocked
Track aligners fix phase between microphones. Meters just point at the problem. Fiix finds the frequency zones where your master genuinely cancels in mono and repairs them in real time, so the fold-down comes back as level. There is no gain stage in the box, yet the mono fold gets louder. The mid channel is mathematically untouched, always.

Insert Fiix last on the chain and press play. LEARN listens for twenty seconds, places the crossovers around the exact frequency regions that cancel in mono, sets Sub Lock and writes a plain-English summary of what it found. UNDO restores your previous zones. Everything after that is automatic.

MONO RECOVERED is the number no other meter shows: how much level and tone Fiix returns to your mix when a phone or club rig folds it to mono. Already safe? It says so, and leaves the track alone. Turn on DELTA and solo a band to hear exactly what is being removed. Silence means nothing needed fixing.

When the pass is done, one click writes a branded Phase Report: the verdict, how much mono loss you recovered, every band’s health, and each timestamped fix with its bar number and frequency range. A clean, shareable document you can send straight to the mix engineer or drop into a master delivery.

The MODE switch sets how hard Fiix may work. SURGICAL is full authority. SOFT is gentle correlation nudging: half the rotation and width depth, and a polarity flip has to earn it with a much deeper fault. One-tap PHONE and SPKR previews fold the output through a tiny speaker so you hear what the listener gets, and the bypass A/B is loudness-matched, so the louder side can never win the comparison.
Fiix re-aligns inter-channel timing faults, rotates drifted phase back into place and rescues genuinely inverted polarity losslessly. It only reduces width as a last resort, so your stereo image stays intact instead of getting sacrificed.
Fiix runs on its Precision engine: linear-phase crossovers and 150 ms lookahead, so fixes land at fault onset with zero phase rotation ever. Playing or recording through it? One switch in the settings drops to a 0 ms zero-latency path. Bypass is a loudness-matched, sample-aligned crossfade, so the louder side can never win the A/B.
| Feature | What it does |
|---|---|
| Automatic phase repair | Finds the frequency zones that cancel in mono and repairs them in real time. |
| LEARN auto-zone | Listens for twenty seconds and places the bands on your material’s trouble regions. |
| Precision mode | Linear-phase crossovers plus 150 ms lookahead so fixes land at fault onset. Zero phase rotation. |
| Zero-latency option | One switch in settings: 0 ms for tracking and live paths. |
| Spectral Reduce | Pulls down only the exact frequencies that cancel in mono, and nothing else. The mid is never touched, so it can never colour the pitch. |
| MONO RECOVERED meter | How much mono level Fiix wins back, with the raw loss in and out, overall and per band, pre and post. |
| Timing + phase align | Re-aligns inter-channel delay and rotates drifted phase back into place. |
| Polarity rescue | Flips a genuinely inverted band losslessly instead of reducing it. |
| Sub Lock | Keeps the low end phase-coherent for punch that survives the club. |
| Delta solo | Hear exactly what is being removed. Silence means nothing needed fixing. |
| Event log + Phase Report | Timestamped fixes and a branded PDF you can send the client. |
| Soft / Surgical mode | Pick the repair character: full authority, or gentle nudging at half depth. |
| Translation previews | One-tap phone and small-speaker folds, so you hear what the listener gets. |
| Mono verdict + score | A bass-weighted 0-100 score and a clear MONO SAFE / CAUTION / RISK call. |
| Waterfall view | The correlation terrain over time, so trouble that comes and goes leaves a trail. |
| Matched A/B | Bypass is loudness-matched, so the louder side can never win the comparison. |
| Dead Quiet skin | The black, red and bone brand look, one click in the settings. |
| Settings export | Every parameter to a file, for recall notes and moving rigs. |
| Zero added colour | The mid channel is mathematically untouched, always. |