The KEF Ci160RR-THX is a round in-ceiling speaker built for serious home cinema: a THX Certified Ultra architectural loudspeaker engineered to keep its sound quality intact at high output, whether it is covering overhead channels in a Dolby Atmos layout, a surround position, or foreground music in a room where nothing but a paintable grille should be visible. It belongs to KEF's Ci-R Series, the middle of the three architectural tiers KEF offers (Ci-Q Series, Ci-R Series and Ci-Reference), and it can be installed in a ceiling or a wall.
Uni-Q Driver Technology
At the heart of the Ci160RR-THX is KEF's Uni-Q driver array. A 25mm aluminium dome tweeter is mounted at the acoustic centre of the 165mm low frequency woofer, so high and low frequencies originate from the same point in space. KEF calls this the "Sit Anywhere" arrangement: the acoustic lobing common to conventional two-way designs is virtually eliminated, dispersion is wide, and the tonal balance stays consistent throughout the room rather than only at a single sweet spot. The Tangerine Waveguide fitted over the tweeter protects the dome and further broadens its dispersion, giving the speaker a nominal coverage of 130 degrees. The two drivers cross over at 2.1kHz, and the high-power tweeter is designed to deliver continuously high output without audible distortion.
THX Certified Ultra
THX Ultra certification is a third-party performance standard rather than a marketing badge. KEF states that the Ci160RR-THX endured nearly 500 THX laboratory tests on the way to certification, and the speaker is rated for a maximum SPL of 105dB at 1m. In open-backed use the frequency response is 52Hz to 24kHz (plus or minus 6dB) with a -10dB range of 38Hz to 30kHz; sensitivity is 90dB (2.83V/1m) into a 4 ohm nominal load, and KEF recommends amplifiers of 10 to 190W with a high-pass filter at 38Hz. To meet the THX Ultra distortion specification the speaker must be installed with a 3 litre rear enclosure and the AV processor speaker size set to Small. KEF does not list a dedicated rear enclosure for this model, so the installer provides one to suit the build.
Built for Installation Environments
The Ci160RR-THX carries IP64 certification, having passed official IEC testing to confirm that splashing water has no harmful effect on the assembly. A proprietary plating and powder coating process gives the speaker UV protection and lets it withstand harsh operating environments. The ABS bezel is engineered to be as thin as possible while keeping its structural rigidity, the crossover is enclosed in a protective cover that also stiffens the assembly, and connection is by gold-plated spring-loaded binding posts that guarantee consistent clamping pressure on the cable. The grille attaches by a powerful magnetic circuit, with no visible fixings, and can be painted to match the ceiling.
Installation and Compatibility
KEF's Universal Cut-out system means every KEF 160mm round in-ceiling speaker uses the same 196mm opening, so the Ci160RR-THX can be fitted into an existing KEF 160mm aperture without re-cutting, and models can be mixed across a project without changing the hole size. The speaker measures 234.6mm across the bezel and 115mm deep, with a mounting depth of 110mm behind the ceiling surface, and it accepts ceiling thicknesses from 5mm to 37mm. For new-build installations KEF offers the optional RIF160R rough-in frame. Where the speaker is used open-backed, KEF specifies an ideal rear volume of 20 litres and a minimum of 10 litres. Net weight is 2.94kg. Sold as a single speaker.