Short answer: the CI250RRM-THX is for immersive audio or full-range ceiling duty; the CI50R is only for tiny legacy ambient-audio locations.
The CI250RRM-THX has the scale for real system use. Its 10-inch woofer, 4-inch Uni-Q midrange, and 1-inch tweeter reach 51.3Hz at -3dB and are deliberately optimized for typical off-axis ceiling listening. It is THX certified and benefits from room correction.
The CI50R is constrained by its micro enclosure. It fits an 80mm square, 55mm-deep space, but its 2-inch full-range driver rolls off around 170Hz at -3dB. It is discontinued and should be treated as a specialty fill rather than a current main, surround, or height speaker.
Buy the CI250RRM-THX for any demanding ceiling-channel role.
Buy the CI50R only when no larger speaker can physically be installed.
Looking for alternatives? See the complete Passive Home rankings.
An in-ceiling speaker with very deep bass for its type, voiced for Atmos height or surround channels and great with room correction.
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Specifications Side By Side
| KEF CI250RRM-THX | KEF CI50R | |
|---|---|---|
| Price | $4,395.90 per pair | $99.99 per pair Discontinued |
| Ranked | #7 of 28 in In-Wall & In-Ceiling Speakers | #25 of 28 in In-Wall & In-Ceiling Speakers |
| Drivers | 10” LF woofer, 4” Uni-Q midrange, 1” vented aluminum dome tweeter with MAT (3-way coaxial) | 2” full-range driver |
| Enclosure | Open-backed, in-ceiling | Open-backed (optional rear enclosure), in-ceiling |
| Mounting Cutout | 300mm (11.81 in) | 70mm (2.76 in) with rear enclosure |
| Dimensions | 13.6” x 13.6” x 6.9” (346 x 346 x 175 mm) (168mm mounting depth) | 3.1” x 3.1” x 2.2” (80 x 80 x 55 mm) |
| Weight | 13.2 lbs (6 kg) | 2.2 lbs (1.0kg) |
| Sensitivity | 89dB | 82dB |
| Impedance | 8 ohms | 6 ohms |
| Power Handling | 50-250W recommended amplifier power | 10-30W recommended amplifier power |
| Frequency Response | 28Hz-20kHz +/-6dB (manufacturer, open-backed) | 125Hz-20kHz +/-6dB (manufacturer, open-backed) |
| Bass Extension (-3dB) | 51.3Hz (measured, spinorama.org ASR data) | 170Hz (measured, spinorama.org vendor data) |
| Bass Extension (-10dB) | 23.3Hz (measured, spinorama.org ASR data) | 113Hz (measured, spinorama.org vendor data) |
| Certification | THX | - |
| Spinorama Preference Score | 4.67 | - |
| Spinorama Preference Score with Perfect Sub | 6.68 | - |
| DIY Kit | No | No |
Frequency Response Compared
Both speakers’ spinorama measurements, overlaid. A flatter line is more neutral: peaks sound forward or harsh, dips sound recessed. Each curve is shifted so its average from 300 Hz to 3 kHz sits at 0 dB, so loudness differences between the two are removed and only the shape is compared. The two were measured by different sources, so small differences, especially in the bass, can come from the measurement setup rather than the speakers.
Measurement data: KEF CI250RRM-THX (measured by Audio Science Review) and KEF CI50R (measured by the manufacturer), via spinorama.org.
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