Passive · 3D-printed composite · Mundorf AMT

COBRA

Big sound. Not big speakers.

Four long-throw 7″ Epique drivers and twelve passive radiators per pair — the moving air of a 15-inch subwoofer, in a monitor that fits a bookshelf. Fully passive, so your amplifier stays your choice.

Free insured worldwide shipping  ·  3-year warranty  ·  30-day home trial  ·  Built in the sequence orders arrive

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Passive · Mundorf AMT

COBRA

Big sound. Not big speakers.

The moving air of a 15-inch subwoofer, in a monitor that fits a bookshelf.

Order a pair

Hear them first
01 / The problem

What Cobra answers with

Big scale.
Big sound.
Total immersion.
Small footprint.

High-end audio asks you to give something up.

Money, floor space, or control over your own system. Usually two of the three.
The price

€30,000 for a painted MDF box.

Then €50,000. Then €100,000. Inside: ordinary drivers, ordinary cabinets, and a story. High-end pricing stopped being grounded in what is actually in the speaker.

The size

“Want big sound? Buy big boxes.”

So the living room becomes a showroom, your partner stops speaking to the speakers — and a surprising number of them still do not sound big.
The trap

Active means somebody else chose.

Chasing real dynamics pushes you toward active designs. Your amplifier is picked for you, tuning is gone, and when the built-in electronics die, so does the speaker.

Why we built Cobra

The speaker we wanted did not exist.

Compact, concert-scale, honestly priced, fully passive. Twenty years of building drivers and cabinets went into proving all four can be true at once.
02 / Independent review

“Where Viper is still sane, Cobra is completely bonkers.”

“By late November 2025, I found myself once again staring at a personal first: true unconditional full-range performance bottled by a passive bookshelf speaker then uncorked at a scale that just shouldn’t be.”

“Once more, Cobra’s tweeter preceded by its custom silver/gold wiring and filter parts overtook my former triumvirate to usurp the Treble High Throne.”

Srajan Ebaen · 6moons

Read the full review
03 / The idea

A monitor that behaves like a full-range system.

Cobra is not a bookshelf speaker with ambition. It is a ground-up redesign that borrows one property from each thing it competes with.
Impact

of a large floorstander
Scale

of a full-range system
Air

of an open-back dipole
Precision

of a studio monitor
Freedom

of a fully passive design — you choose the amplifier, for the whole life of the speaker
Designed by Grzegorz Rulka

Audio is art guided by physics.

Co-founder of Cube Audio and Qualio Audio, creator of Virtual HiFi, with a background in technical physics and engineering. Twenty years of designing and manufacturing fullrange drivers, crossovers and cabinets. You need engineering to build it — and artistry to make it alive.
04 / The engineering

Where the big sound actually comes from.

Three decisions, none of them cheap, none of them marketing.

15.5″

equivalent moving area per speaker, from 7″ drivers

19 mm

Xmax on every driver and every radiator

10×

better vibration suppression than 22 mm MDF

10 mm

total wall thickness, and 20% more internal volume
The cabinet

A wall that turns sound into heat.

A 5 mm printed PETG shell, a 5 mm internal diamond-brace grid, and the cavities between them filled with 35A elastomer loaded with stainless-steel micro-particles.

That is a constrained-layer-damping composite: panel energy is converted to heat instead of being radiated back into the room. The result is an enclosure that is effectively silent — at 10 mm thickness, while keeping 20% more volume for bass than a thick-walled box of the same size.

The tweeter mount

On top of the box, not in it.

The open-back Mundorf AMT sits on a printed TPU elastomer isolation frame above the cabinet, completely decoupled from it.

No cabinet vibration reaches the diaphragm, so its microscopic detail survives. It also puts the tweeter where time alignment wants it, and lets the dipole radiate freely to the rear.
05 / Passive radiators

Twelve cones with no magnets, doing the work of a 15-inch woofer.

The part of Cobra most people have never seen in a speaker this size — because of what it costs.

A passive radiator is a speaker cone without a magnet. It moves only because the air inside the enclosure pushes and pulls it — when the main driver changes internal pressure, the radiators follow.

At the resonant frequency they move in sync with the driver, and at bass frequencies they behave as additional woofers equal to their combined surface area. They also supply the spring that would otherwise demand a large internal air volume — so the box gets smaller and the bass gets faster.

A reflex port does a cruder version of this for a few dollars, with port noise and compression as the price. That is why almost everyone uses one.

Four Epique drivers and twelve passive radiators — in one pair of “monitors”.
What is inside each pair

€840

value of the radiators in one pair

Twelve high-performance Epique radiators, at €70 each. A reflex port costs a few dollars and does a cruder job — which is why almost every speaker has one. For a high-end design where cost is supposedly no object, leaving out the radiators is harder to explain: the performance they buy is enormous.
06 / The tweeter

Mundorf AMT25D1.1, and thirteen times the air.

The reviewer who has heard most of the alternatives put this one on the throne.

Its pleated diaphragm has a radiating surface over 13× larger than a typical 1″ dome. More area means more air moved for the same excursion — effortless dynamics instead of strained ones.

Because it is a dipole it radiates forward and backward, roughly doubling acoustic output and opening a soundstage no dome can produce. It is filtered through Jantzen Amber copper-foil capacitors, so what reaches it has nothing added.

Radiating area

13× a 1″ dome
Radiation

Open-back dipole
Mounting

Elastomer isolation frame, above the cabinet
07 / Components

The parts list you are normally not shown.

Most speakers at this level put the money into the cabinet finish. Open ours and the money is in the signal path.
Dimensions

55 × 20 × 32 cm (H×W×D) · 20 kg each
40 cm cabinet (two modules) + 15 cm of AMT above it
Tweeter

Mundorf AMT25D1.1 dipole
Transducers

Dayton Epique 7″ carbon-fibre drivers and radiators
Capacitors

Jantzen Amber copper foil · ClarityCap PUR
Coils

Jantzen Litz
Resistors

Mundorf Supreme, non-inductive
Terminals

WBT NextGen pure silver
Wiring

Duelund internal cabling

This is the component set you find in €30,000–€100,000 speakers. Cobra is built like one, and priced like a speaker rather than a story.
08 / The sound

Looks like a monitor. Sounds like a beast.

Recorded in our studio with high-end microphones — same room, same chain, no processing. Headphones or a good system recommended.
Bass and dynamics

Immediate, deep, physical — the kind that pushes air and hits your chest. Explosive and effortless: drums sound like drums, pianos have weight and authority.

Stage and treble

Open, holographic, three-dimensional. The dipole AMT fills the room with air and realism, and voices arrive lifelike rather than projected.

At both extremes

Warm, textured and detailed at whisper level. Loud without strain, distortion or compression at the other end. No stage where it stops being enjoyable.

Recording session — Cobra captured with high-end microphones in our studio.
09 / Tuning

Warm. Neutral. Studio. Airy.

Every room is different, and so is every listener. A five-step plug-in resistor sets the level of the open-back AMT — five seconds, no switches in the signal path.

Five-step plug-in resistor, no soldering

Zero-loss pure silver WBT NextGen contact

No sound-degrading rotary switches anywhere

Takes about five seconds to change

Set it once for the room, or change it per record

This is what a passive design buys you that an active one cannot: the speaker adapts to your room and your taste rather than to a firmware decision made in a factory.
10 / Where’s the catch

And what you get for it

Your amplifier stays your choice — for as long as you own them.

No built-in electronics to fail, date or dictate. Upgrade the amp in ten years and Cobra improves with it.

They need a real amplifier.

That is the honest trade. Sixteen long-throw cones per pair need current and grip, and we would rather tell you now than after delivery.

200–500 W

Per channel into 4 Ω. Below that the drivers never get the control they were designed around.

Class D or AB

Either works well. What matters is a neutral character and the ability to deliver current on demand.

Damping factor

A good one. This is what keeps the long-throw woofers and the radiator system under command in the bottom octaves.

Not sure?

Send us what you own.

We will tell you honestly whether your amplifier is up to it — including when the answer is no.

Ask on WhatsApp
11 / Made to order

Printed for you, in your colours.

Nothing sits on a shelf waiting for an order. Every pair starts when you place one.
Customisation

Magnetic front panels, swapped anytime.

Printed to order in premium BambuLab and FiberLogy materials. Choose the cabinet colour, the front panel colour and the finish — and because the front panels are magnetic, change your mind later without touching a tool. Bespoke requests handled case by case.

Limited production

600 hours of printing. 100 hours of testing.

Combined print time per pair is around 600 hours. Assembly is by hand in Poland, and each pair is then individually tested for 100 hours before it ships. Capacity is deliberately limited — if the queue is full, you wait.

55 × 20 × 32 cm

H × W × D, 20 kg each. The cabinet is 40 cm — two stacked modules — and the AMT stands 15 cm above it.

4 Ω

Nominal impedance, fully passive crossover.

Stands

Not included. Cobra is a monitor and wants ear-height placement.

Five finishes

Black, white, gray, beige — or tell us what you want. Same price.
12 / Owner reviews

What owners say after living with them.

Verified reviews collected through Loox after purchase — from people who put the Cobras in their own rooms, on their own amplifiers.
13 / How this goes

Three simple steps to better sound.

Hearing them in your own room, on your own system, is the only test that settles a speaker at this price.

01

Choose your Cobra.

Pick the cabinet and panel colours. Tell us your room and your amplifier at the same time and we will confirm the fit before we start.

02

We build it for you.

Printed, hand-assembled, fine-tuned and tested in Poland, then sent by insured FedEx airmail — roughly a week in transit once it ships.

03

Live with them for 30 days.

Your room, your system, your music. If Cobra does not move you, send it back inside 30 days. No questions, no pressure.

Cobra is built for people who want to experience music, not marketing. The trial exists because that claim should cost us something, not you.

Start with step one
14 / How to order

Straight from the workshop.

Over 1,000 orders shipped worldwide across the Virtual HiFi products range, each one packed and sent by the people who built it.
Factory direct · per pair

Built to order, sent straight to you.

Price is for a pair; stands are not included. EU orders add 23% VAT at checkout, and the final figure appears in your cart in your own currency. Orders are fulfilled in the sequence they are received.

Order a pair

Free insured FedEx airmail, worldwide

Roughly one week in transit from dispatch

3-year warranty · 30-day return

A direct line to the people who built them

Colours chosen at checkout, all the same price

EU VAT

23% added at checkout. Buying as a business with a valid EU VAT number? Ask us for a 0% invoice.

Outside the EU

Local duties may apply — currently 15% into the US. FedEx may email you a short import form.

Build queue

600 hours of printing and 100 hours of testing per pair. Typical lead time is 3–4 weeks.

1,000+ shipped

Delivered worldwide across the full Virtual HiFi products range.
Cobra

High end. No myths.

Tell us your room and your amplifier. If Cobra is wrong for you, we will say so — that conversation costs nothing and saves everyone time.

Order a pair

Ask on WhatsApp

Send a message
15 / Buy Cobra

Choose your finish and order.

Price shown in your own currency. EU orders add 23% VAT at checkout. Stands are not included.
Cobra Monitor.
Cobra Monitor.

Cobra Monitor

47.374,00 zł

Per Pair

Cobra monitors deliver true high-end sound without the industry hype. Crafted for discerning listeners, they combine precision 3D-printed enclosures, premium Mundorf AMT tweeters, and deep, controlled bass from 12 advanced passive radiators.

Experience uncompromising, big high-end speaker performance — available from select local dealers or direct-to-consumer at exceptional value. 
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