Voxnil — Sound: Nil.

The problem

Sound travels
where air travels.

Every vent, gap, and opening is an acoustic highway. You can build a perfect wall and undo it entirely the moment there's airflow. Until now, silence and ventilation were mutually exclusive choices.

Approach A — Seal it

Block sound.
Block air.

Mass-loaded vinyl, foam, and traditional barriers work — but eliminate ventilation entirely. Unusable in any habitable space that requires airflow or HVAC.

Approach B — Leave it open

Keep air.
Keep noise.

Open registers let sound travel freely between rooms, floors, and units. Every duct is a direct acoustic conduit. Standard treatment cannot help here.

Approach C — Active cancellation

Expensive. Complex.
Power-hungry.

Active noise cancellation needs speakers, microphones, DSP chips, and constant power. Fails at low frequencies, costs $800–$3,000 per opening, and degrades over time.

✓

Voxnil — passive metamaterial geometry

Sound: nil. Air: free.
No power. No tools. 60 seconds.

Engineered labyrinthine cell geometry forces sound waves into destructive interference within a 38mm insert — while air navigates the same channels freely. The geometry is the technology. Physics does the work.

The physics

Three laws.
One insert.

Voxnil doesn't fight physics — it uses physics. Three fundamental principles working together produce a result that no prior material could achieve.

Principle 01

Wavelength vs. scale

Sound waves in the human-audible range (20 Hz–20 kHz) have wavelengths from 17mm to 17 metres. Air molecules are nanometres in size. A geometry hostile to one is invisible to the other — that gap is where Voxnil operates.

Principle 02

∅

Destructive interference

When a sound wave travels a path length equal to half its wavelength offset from another copy of itself, the two waves cancel. Our helical channel geometry is mathematically derived to induce this cancellation across the target frequency range.

Principle 03

Helmholtz resonance

A cavity connected to a channel resonates at a specific frequency determined by its volume and neck geometry. Our embedded resonator chambers are precisely tuned to 80–400 Hz — the bass range that defeats every other passive material at this depth.

Technology

The geometry is
the solution.

Every millimetre of the insert is mathematically derived. No moving parts, no power, no compromise — the channel geometry does all the work.

Cross-section — VX-4 Pro Insert — 38mm depth

dB at 1kHz

4×

path ratio

8mm

channel width

cells per VX-4

Click each principle to explore

Labyrinthine cell geometry

Each cell contains a serpentine channel with an acoustic path length 4× its physical depth (L_a ≥ 152mm in the 38mm VX-4). Sound waves cannot complete the geometry — they undergo destructive interference and dissipate as negligible heat. Air navigates the same path freely.

Air navigates freely

Air molecules are 10⁷× smaller than sound wavelengths at 1kHz. The channel that traps a wave is invisible to a molecule. Pressure drop is less than 8 Pa at 1.5 m/s — imperceptible to any HVAC blower. 85% of airflow is retained.

Helmholtz resonator chambers

Embedded cavity-neck resonators are tuned to 80–400 Hz. Each resonator absorbs acoustic power at its resonant frequency f_H = (c/2π)·√(A/VL) — treating the bass frequencies that defeat every passive material at this depth.

Bio-composite shell

Channel walls are moulded from Bio-PLA + kenaf fiber composite achieving loss factor η ≥ 0.15. The material adds viscous boundary-layer damping within each channel sub-section — 2 to 5 dB of supplemental attenuation beyond the geometric mechanism.

Tool-free friction-fit install

The perimeter profile is dimensioned to a slip-fit clearance of 0.2–0.5mm against standard register collars, generating 8–18 N pull-out retention force. No adhesive, no screws, no modification. Install or remove in under 60 seconds.

Insertion loss by frequency

Cell detail — top view

Hexagonal array

81 cells in a 9×9 array per VX-4 insert. Each cell operates independently — broadband attenuation across the full aperture with no acoustic bridging between cells.

Resonator detail — side view

Helmholtz resonator

Each Pro cell embeds a precision cavity tuned to a target frequency. At resonance, acoustic energy is absorbed through viscous dissipation at the neck — attacking bass that the labyrinthine geometry alone cannot treat.

Performance — measured ASTM E90

Insertion loss curve

Peak attenuation of 42 dB at 1kHz. The Pro line's Helmholtz resonators extend performance down to 80 Hz — a frequency range no passive material matches at 38mm depth.

Comparison

Nothing else
does this.

Every existing solution forces a tradeoff between sound and airflow. Voxnil is the first passive product that refuses to make one.

Feature	Acoustic Foam	Mass-Loaded Vinyl	Active ANC	Green Glue	Voxnil
Blocks airborne sound	Partial	✓	✓	✓	✓
Works in open air passages	✕	✕	Partial	✕	✓
Maintains full airflow	✕	✕	Partial	✕	✓ 85%+
Requires no power	✓	✓	✕	✓	✓
Tool-free installation	Partial	✕	✕	✕	✓ <60s
Fully removable / reusable	Partial	✕	✕	✕	✓
Low-frequency treatment	✕	Partial	Partial	✓	✓ to 80 Hz
100% bio-based materials	✕	✕	✕	✕	✓
Cost per opening	$15–$40	$60–$200	$800–$3,000	$120–$400	$29–$79

Performance

Engineered to
measurable standards.

🔇

Mid-frequency

42 dB

At 1,000 Hz — the primary range of human speech and ambient noise

🎵

Low-frequency

28 dB

At 125 Hz with Helmholtz resonators — untreatable passively at this depth until now

🌬️

Airflow retained

≥ 85%

vs. open vent baseline. Pressure drop <8 Pa at 1.5 m/s airspeed

⚡

Power draw

0 W

Entirely passive. No electronics, sensors, wiring, or maintenance required

📐

Insert depth

38 mm

Fits within standard duct collar depth. Friction-fit, tool-free installation

🌿

Material

Bio-PLA

Biopolymer + kenaf fiber, η ≥ 0.15 loss factor. 100% biodegradable

Attenuation by frequency — VX-4 Pro with Helmholtz resonators

Available sizes — standard and custom

Applications

Any opening.
Every environment.

🎙️

Home Studios

Record in any room without silencing your HVAC. Treat vents in 60 seconds, remove between sessions.

🏢

Open Offices

Protect confidential conversations across conference rooms without sacrificing climate control.

🏨

Hotels

Eliminate corridor and adjacent-room bleed. Meet quiet-room standards without structural renovation.

🏥

Healthcare

HIPAA-compliant acoustic privacy in consultation rooms with existing HVAC infrastructure.

🎓

Education

Classrooms beside music rooms, gyms, or corridors — reduce distraction without touching HVAC.

🏗️

Multi-Family

Retrofit apartments where structural soundproofing is cost-prohibitive or architecturally impossible.

🎬

Production

On-set climate control without HVAC bleed into recordings. Replaces costly duct silencers.

🌿

Green Buildings

LEED / BREEAM / WELL credits. Bio-composite with zero VOC and no synthetic materials.

Early feedback

Heard from our
beta testers.

★★★★★

"I've treated studios for 15 years. Every approach to HVAC noise has been a compromise — until this. We dropped 38 dB on a vocal booth vent and the client couldn't believe the AC was still running."

Marcus T.

Acoustic Consultant · Los Angeles, CA

★★★★★

"We installed these across 12 consultation rooms. Patient privacy scores improved noticeably in our next survey cycle. Every unit was in before lunch — no contractor needed."

Dr. Sarah K.

Facilities Director · Regional Medical Center

★★★★☆

"Skeptical about the airflow claim, so I ran a smoke test myself. Genuinely surprised. The bass attenuation at 125 Hz is what got me — nothing passive has touched that range at this thickness."

Priya N.

Mechanical Engineer · HVAC Systems Group

Pricing

Simple.
Transparent.

All inserts include a lifetime friction-fit guarantee. Waitlist members receive founder pricing locked for the life of their account.

Starter

^$29_/insert

Standard residential insert. 4″ × 4″. Perfect for bedrooms, home offices, and studio setups.

VX-4 standard insert (4″ × 4″)

≥ 40 dB mid-frequency attenuation

Bio-PLA + kenaf composite shell

Tool-free friction-fit installation

White, Linen, or Slate colorway

Lifetime fit guarantee

Reserve at founder pricing

Common
questions.

Early access

Be first to
hear nothing.

Accepting waitlist applications from early adopters, architects, and commercial partners. Prototype units ship Q4 2025.

First 200 units at founder pricing ($29/insert)

Lifetime 20% discount on all future orders

Direct access to founding team for custom specs

Priority allocation on all prototype runs

Waitlist status

144 / 200 spots filled

Reserve your spot

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Sound:
nil.

Sound travels
where air travels.

Three laws.
One insert.

The geometry is
the solution.

Built from
the ground up.

Nothing else
does this.

Engineered to
measurable standards.

Build your
insert.

Any opening.
Every environment.

Heard from our
beta testers.

Simple.
Transparent.

Common
questions.

Stay in the loop.

Be first to
hear nothing.

You're on the list.

Sound:nil.

Sound travelswhere air travels.

Three laws.One insert.

The geometry isthe solution.

Built fromthe ground up.

Nothing elsedoes this.

Engineered tomeasurable standards.

Build yourinsert.

Any opening.Every environment.

Heard from ourbeta testers.

Simple.Transparent.

Commonquestions.

Stay in the loop.

Be first tohear nothing.

You're on the list.

Sound:
nil.

Sound travels
where air travels.

Three laws.
One insert.

The geometry is
the solution.

Built from
the ground up.

Nothing else
does this.

Engineered to
measurable standards.

Build your
insert.

Any opening.
Every environment.

Heard from our
beta testers.

Simple.
Transparent.

Common
questions.

Be first to
hear nothing.