KEF Ci200RR-THX In-Ceiling Speaker (Single)

The KEF Ci200RR-THX sits at the top of KEF’s Ci R Series — a range of custom-installation speakers that draws its acoustic DNA from the company’s acclaimed R Series floorstanding loudspeakers. Certified to THX Ultra2 standard, the Ci200RR-THX is an in-ceiling LCR (Left/Centre/Right) speaker engineered to deliver the tonal balance and dynamic impact of a traditional box speaker from within a flush-mounted ceiling installation, making it suitable for dedicated home cinema rooms of any size.

Uni-Q Driver Array

At the heart of the Ci200RR-THX is KEF’s signature Uni-Q driver array, which places the 38mm (1.5”) aluminium dome tweeter concentrically within the 200mm (8”) bass driver. This coaxial arrangement ensures that both high and low frequencies radiate from a single acoustic point source, producing more accurate stereo imaging and a wider listening area than conventional two-way designs — particularly important in ceiling-mounted applications where off-axis listening angles are the norm rather than the exception.

Tweeter & Waveguide

The tweeter uses a vented aluminium dome coupled to a 38mm voice coil — significantly larger than a typical in-ceiling tweeter — and is loaded with KEF’s tangerine waveguide. The waveguide’s ribbed geometry controls high-frequency dispersion, smoothing the off-axis response to maintain tonal consistency across the listening area. The vented dome design allows the rear wave of the diaphragm to escape, reducing back-pressure distortion at high output levels.

Bass Driver & Z-Flex Surround

The 200mm woofer is built around an oversized magnet structure that delivers the motor force necessary for high-excursion bass reproduction in an open-backed ceiling cavity. The Z-flex surround — a proprietary KEF design — replaces the conventional half-roll rubber surround with a flexible, corrugated profile that permits greater linear cone travel. This combination enables the Ci200RR-THX to reach down to 33Hz, unusually deep for a single in-ceiling driver.

THX Ultra2 Certification

THX Ultra2 certification means the Ci200RR-THX has been independently tested and verified to meet the performance standards originally developed for professional cinema monitoring. THX Ultra2 speakers must deliver reference-level output, controlled directivity, and flat frequency response within defined tolerances — ensuring that film soundtracks are reproduced with the tonal balance intended by the filmmaker’s final mix. Action sequences are delivered with full dynamic impact, while dialogue remains natural and intelligible.

Installation

The round-format design fits a 238mm ceiling cut-out and requires a minimum mounting depth of 126.5mm. Ceiling thickness must be between 6mm and 37mm. The Ci R Series is designed as a complete architectural cinema system: the Ci200RR-THX can be combined with KEF’s complementary in-wall models and a powered subwoofer to build a fully THX-certified surround sound installation without any freestanding loudspeakers.