The KEF Ci160RR-THX occupies the upper tier of KEF's Ci THX Reference Series, a range of architectural loudspeakers engineered to satisfy the exacting performance requirements of THX Certified Ultra installations. Where most in-ceiling speakers represent a compromise between acoustic performance and discreet aesthetics, the Ci160RR-THX refuses that trade-off: it is built to deliver genuine home cinema reference performance from a completely flush, round aperture with nothing visible but a magnetic grille.
Uni-Q Driver Technology
At the heart of the Ci160RR-THX is KEF's signature Uni-Q driver array. A 25mm aluminium dome tweeter is mounted precisely at the acoustic centre of a 165mm (6.5-inch) bass/midrange driver, creating what KEF describes as a coincident point source. Because the high and low frequencies originate from a single point rather than from spatially separated drivers, the Ci160RR-THX produces a large, coherent soundstage with consistent tonal balance at virtually any listening position within the room. The Tangerine Waveguide fitted to the tweeter broadens its dispersion and maintains smooth high-frequency response across a wide coverage angle, ensuring even coverage in larger home cinema rooms.
Z-Flex Surround and Bass Performance
The 165mm woofer uses KEF's Z-Flex surround geometry, which allows the cone to travel further without the stiffness and distortion that a conventional roll surround would introduce at higher excursions. This contributes to the Ci160RR-THX's ability to reach down to 38Hz, a frequency extension that is exceptional for a speaker of this size and particularly valuable in home cinema applications where low-frequency content from film soundtracks must be reproduced accurately rather than passed entirely to a subwoofer.
THX Certified Ultra
THX certification is not a marketing designation: it is a performance standard that requires a speaker to demonstrate specified maximum output levels, low distortion, and correct tonal balance under third-party test conditions. The Ci160RR-THX holds THX Ultra certification, the standard intended for large dedicated home cinema rooms. To achieve full THX Ultra compliance, the speaker should be installed with a 3-litre rear enclosure (available separately from KEF), and the AV processor speaker size should be set to Small. The certification ensures the Ci160RR-THX will perform as intended in a correctly configured surround-sound system.
Installation and Compatibility
KEF's Universal Cut-out system means the Ci160RR-THX uses the same 196mm cut-out diameter as other KEF 160mm series speakers. This simplifies upgrades in existing installations: a room previously fitted with KEF Ci Series Q-range speakers can accept the Ci160RR-THX in the same apertures, without re-cutting. The speaker is secured using KEF's Trimless installation bracket, and the magnetic grille attaches without visible fixings. The result is a completely flush finish with no visible screws, clips, or trim rings.