THX® Certified Ultra. MAT™ Inside. The Most Advanced Architectural Speaker KEF Has Ever Built.

The KEF Ci250RRM‑THX represents a new era in architectural loudspeaker engineering — a revolutionary coaxial three‑way in‑ceiling speaker that combines KEF’s most advanced acoustic technologies into a single, ultra‑high‑performance design. Certified to THX® Ultra, it delivers true cinema‑grade dynamics, precision, and tonal accuracy for large home theatres and premium living spaces.

At the heart of the Ci250RRM‑THX is the 12th Generation Uni‑Q® driver array with MAT™ (Metamaterial Absorption Technology). This groundbreaking acoustic innovation absorbs 99% of unwanted sound from the rear of the tweeter, resulting in cleaner, more natural treble and exceptional detail. The Uni‑Q acts as a single point source, ensuring wide, even dispersion so every listener enjoys the same immersive soundstage.

KEF’s engineering team pushed boundaries even further with two major innovations:

Cavity Radiation Control (CRC)

A patent‑pending open‑back midrange design using acoustically absorptive foam to eliminate midrange dips — up to 30 dB in typical coaxial designs. The result is the most accurate, realistic midrange performance ever achieved in an architectural speaker.

Low Diffraction LF Aperture

A carefully sculpted housing with an absorptive outer ring that reduces resonance and diffraction, preserving mid/high clarity while allowing the 250 mm (10 in.) LF driver to deliver deep, room‑filling bass down to 28 Hz.

With a maximum SPL of 111 dB, the Ci250RRM‑THX delivers breathtaking dynamics, cinematic impact, and reference‑grade fidelity — all from a discreet in‑ceiling form factor. Its Ultra‑Thin Bezel (UTB) and paintable magnetic grille ensure seamless architectural integration, while the IP64 rating provides protection against dust and splashes.

Designed for Extreme Home Theatre, the Ci250RRM‑THX is the pinnacle of KEF’s architectural engineering — powerful, precise, and built for the most demanding installations.