KEF’s First Architectural Speaker with MAT™
Featuring innovative technologies including 12th Generation Uni-Q® driver array with Metamaterial Absorption Technology (MAT), patent-pending Cavity Radiation Control and Low Diffraction LF Aperture, Ci250RRM-THX is a truly revolutionary coaxial three-way architectural speaker that delivers immersive, high-fidelity soundstage with unmatched sonic excellence for large home theatres and living rooms.
Pushing technological boundaries
KEF always pushes the technological boundaries in its mission to create the best possible sound; Ci250RRM-THX is the physical manifestation of that drive.
Ci250RRM-THX delivers ultra-high performance with true theatre sound quality for large theatres and living rooms and it is certified to THX® Ultra. A deep understanding of the filmmaking process and surround sound is at the very heart of every THX® certified speaker system. Engineered with design characteristics of professional studio speakers, THX® recreates the tonal balance of the filmmaker's final mix in your home theatre or living room. The results? Action sequences are impactful, and dialogue-driven moments are natural and engaging.
Frequency Response (±6dB) Open-backed
28Hz - 20kHz
Frequency Range (-10dB)
20Hz - 45kHz
Nominal Coverage (Degrees)
LF: 250mm (10in.)
MF: 100mm (4in.) Uni-Q
HF: 19mm (0.75in.) vented aluminium dome with Metamaterial Absorption Technology1
Recommended Amplifier Power
50 - 250W
Recommended High-pass Filter (Hz)
30 - 60Hz
Product External Dimension
Diameter Ø: 346mm (13.62in.)
Depth: 175mm (6.89in.)
Diameter Ø: 300mm (11.81in.)
Mounting Depth from Surface
Optional Rough In Frame
Ideal Rear Volume
Minimum Rear Volume
THX® Certified Ultra
Safety and Regulatory Compliance
Ceiling thickness (Maximum)
Ceiling thickness (Minimum)
ManualIndividual Information Spec. SheetArchitectural Speakers BrochureCi Series Spec. SheetCi Series Minimum Cabinet Volume ChartCutout TemplateEASE GLL DATAProduct DrawingCi Series PamphletCi Accessory GuideWhite paper
KEF reserves the right, in line with continuing research and development, to amend or change specifications. E&OE. THX, the THX logo, and Ultra are trademarks of THX Ltd. THX and the THX logo are registered in the U.S. and other jurisdictions. All rights reserved.