Silence, engineered.
A single monolithic tower, hand-built in Zurich. Four drivers in a constrained-layer cabinet, tuned to disappear, so that all that is left in the room is the recording and one chair.
The Object · One Tower
The MONO-9 is a single 1,240 mm column of brushed aluminium and black lacquer. No grille, no ornament, nothing to soften the edge. Orbit it slowly, from full height to the driver array to the rear port.
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View · From the Floor
One machined column, front baffle in brushed aluminium, cabinet in seven coats of hand-rubbed black lacquer. It stands 1,240 mm and weighs 41 kilograms because mass is what silence costs.
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View · Baffle Detail
A 29 mm beryllium dome sits above a 150 mm midrange and two 220 mm woven-fibre woofers, each ringed in a machined alloy surround. Every cone is measured, matched to its pair within 0.2 dB, and numbered.
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View · Rear Spine
From behind, the tower is all machined spine. A single flared port runs the full height, laminar-tuned to 28 Hz so the low end arrives as pressure, not as noise. The seam between alloy and lacquer is one continuous line.
Anatomy · Section 001
Cut the MONO-9 in half and there is nothing decorative inside. Bracing, crossover, magnet and dome, each solving one problem and adding none. Move the pointer to read the section.
01 · Tweeter
29 mm beryllium dome
Ferrofluid-cooled, decoupled from the baffle. Reaches 40 kHz without breakup.
02 · Crossover
4th-order, hand-wired
Air-core coils and polypropylene caps on a floating board. Split at 320 Hz and 2.6 kHz.
03 · Midrange
150 mm woven fibre
In its own sealed sub-enclosure so the woofers never move its air.
04 · Woofer × 2
220 mm long-throw
Twin motors on a constrained-layer wall. 24 Hz in-room, no port chuff.
The cabinet is not a box with drivers bolted on, it is a braced aluminium lattice poured with constrained-layer damping so the walls stay dead while the cones work. Every part inside answers to one measurement. If it did not lower the noise floor, it is not in the tower.
The Numbers · Measured
Every MONO-9 leaves Zurich with its own measurement sheet, taken in an anechoic chamber at 2.83 volts, one metre. These are the numbers on the card that ships in the crate.
Reference sheet
MONO-9 · Serial-matched
Full bandwidth, minus 3 dB in-room. Sub-bass you feel before you place it.
2.83 V at one metre. Effortless from a good 20 watts, unbothered by 200.
4 ohm nominal, 3.1 ohm minimum. A benign, near-resistive load for any real amplifier.
Constrained-layer baffle, aluminium and viscoelastic core. The walls stay silent.
The Listening Room · One Pair · One Seat
A reference speaker is not furniture, it is an instrument you sit in front of. Place the pair, take the single seat on the axis, and the room falls away. What is left is the stage the engineer heard, rebuilt in front of you in the dark.
Alignment · Toe-in to the seat
Ideal room · 18 to 42 m²
Placement · 0.6 m from the wall
Reserve · MONO-9
Each pair is built to order and numbered. Configure the finish, tell us the room, and reserve your place in the next Zurich build. No payment is taken now, a specialist confirms every order by hand.
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