VORTEX Immersive Downmixer

Fold it down. Get it back.

VORTEX folds your immersive mix — 5.1 up to 9.1.6 — down to any smaller format, stereo or mono, without corrupting your signal. And just like our upmixer, the way back is guaranteed. Simple, easy, effective.

macOS Universal | AAX VST3 Audio Units
Transparent by design

It doesn’t touch your sound

A downmix should be your mix, folded — not a new mix someone else made for you. VORTEX does the fold, shows you what it’s doing, and stays out of the way.

Nothing automatic

No auto-gain, no safety nets, no hidden processing rewriting your fold behind your back. What you hear is your mix.

Nothing in the way

Zero latency, one clean direct fold — never a chain of conversions stacking up inside.

Nothing hidden

Every control shows the real value it’s applying, in dB. Turn a knob and you see exactly what changed. Double-click puts it back.

VORTEX group trims: L/R, C, SIDE, REAR, TOP F, TOP R and DIALOG, each showing its value in dB, with LFE OFF, STEREO LoRo and the Recovery Lock bar reading ITU bit-exact.
Recovery Lock

And you can always come back

VORTEX and the AXIS Upmixer speak the same language — literally the same numbers. Fold your mix down with VORTEX, bring it back up with AXIS, and it’s exactly where you left it.

RECOVERY LOCK

Gold means safe

Your fold is the standard one — the one AXIS knows how to undo. Deliver it with confidence.

CUSTOM FOLD

Red means it’s yours

You’ve shaped the fold on purpose — and the light says so. One click brings you back to the standard.

What keeps Recovery Lock gold

Gold simply means you are still delivering the untouched ITU fold. It stays gold while the mix controls remain at their standard positions:

Group knobs at their ITU values
IN and OUT trims at 0 dB
LFE OFF for stereo or mono
Stereo mode set to LoRo
LIMITER switched off
DIALOG at 0%

Red is not an error: it means you have deliberately made a custom fold. Click the indicator whenever you want to return every relevant control to the ITU values.

Don’t take our word for it.

Upmix with AXIS. Fold with VORTEX. Flip polarity against your original — and listen to it disappear. Silence is the proof.

Measured at −155 dB across the full round trip. Requires AXIS Upmixer v0.7.6 or later.

One plugin, every fold

From any of these… to anything smaller

Atmos beds, 7.1, 5.1, stereo for the client, mono for the phone check — every fold is one clean, direct step. Only the controls your format needs show up.

5.17.15.1.25.1.47.1.27.1.47.1.69.1.49.1.6
 down to 5.1 · stereo · mono — and everything in between
Delivery controls

Protect the fold only when you need to.

VORTEX starts as a pure, zero-latency fold. Dialogue protection and true-peak limiting stay out of the signal until the delivery actually calls for them.

Keep dialogue in front

DIALOG follows the centre channel and gently makes space in everything around it — up to 6 dB — when a stereo or mono fold needs extra intelligibility.

True-peak protection, opt-in

Switch on the 4× true-peak limiter only when the fold exceeds the delivery ceiling. You get an adjustable ceiling and live gain-reduction meter; latency is zero when off and 128 samples when on.

SurroundScope

See what you’re folding

The radar shows your mix from above — with the ceiling on its own scope when your format has height — so you always see what’s about to fold into the bed. No surprises after the bounce.

The Kaizen round trip

Up with AXIS. Down with VORTEX.

Take a stereo track up to immersive with AXIS, mix it in the room, fold it back down with VORTEX — and the original stereo is still there, intact. Two plugins, one promise: your signal never gets corrupted on the way.

AXIS Upmixer and VORTEX Downmixer open side by side on the same session, the upmix on the left and the fold on the right.

Fold with confidence

Try it free for 30 days. Buy when you’re ready.

€99 One-time

Licensed through your Kaizen Audio account — no iLok.

Fold 5.1 up to 9.1.6 down to stereo & mono
Clean and transparent — nothing automatic
Recovery Lock — the way back, guaranteed
True-peak limiter when you want it, off when you don’t
AAX + VST3 + AU · macOS Universal
2 licence seats, online or offline
Free 30-day trial available

Questions? hello@kaizen.audio

User manual

Designed by sound engineers, for sound engineers.

Read the manual

Every format, control and delivery workflow.

The complete 18-section guide covers setup, licensing, ITU folds, Recovery Lock, the limiter, DAW notes and troubleshooting.

Read the VORTEX manual

Frequently asked questions

Which formats and DAWs? +
AAX (Pro Tools 12.8.4 or later), VST3 and AU on macOS 12 or later, Universal (Apple Silicon and Intel).
Do I need an iLok? +
No. Everything is licensed and activated through your Kaizen Audio account.
How do I pick the target format? +
You don’t pick it in a menu — VORTEX folds to whatever your plug-in’s output bus is. Insert the variant whose output matches your target; the footer always shows source ▸ target.
Will my stereo really come back? +
Yes, and you can check it in five minutes: upmix with AXIS (v0.7.6 or later), fold with VORTEX at defaults, invert polarity against the original, and listen to it disappear.
What exactly does “doesn’t corrupt the signal” mean? +
At its defaults, VORTEX applies the published ITU-R BS.775 downmix matrix and nothing else — no auto-gain, no limiting, no hidden processing, zero latency. The fold to stereo uses the ITU rows verbatim, so it’s bit-exact while RECOVERY LOCK shows gold. The full AXIS → VORTEX round trip nulls at −155 dB; VORTEX against the ITU matrix alone nulls at −300 dB.
Is it bit-exact? +
The fold to stereo uses the ITU rows verbatim, so yes — as long as RECOVERY LOCK is gold. Move anything and it turns red and tells you.
Can I chain two instances? +
Use one instance per fold. Going 9.1.6 → 7.1.4 → 2.0 across two instances isn’t identical to folding 9.1.6 → 2.0 directly. One direct fold is the supported workflow.
What about stereo flavours and mono? +
Stereo comes in Lo/Ro and Lt/Rt flavours; mono comes derived from Lo/Ro or straight off the asymmetric BS.775 Table 2 row. Both mono paths are published standards, so neither costs you the lock.
Is there a limiter? +
Yes — a true-peak limiter with inter-sample detection at 4× oversampling, and it’s strictly opt-in. Off means zero latency and zero processing. Nothing rides your fold in the background.
How many machines? +
Two activations per licence. You can move either seat to another computer and use offline activation in isolated rooms.
Is there a trial? +
Yes — a free 30-day trial with everything unlocked, straight from this page. No credit card required.
What about the AXIS Upmixer? +
They’re siblings that speak the same matrix, literally. AXIS guarantees your stereo survives going up; VORTEX guarantees your fold survives coming back down.
Is there a user manual? +
Yes. The complete 18-section VORTEX user manual is available online. Read the manual →