🛠️ In Ceiling & In Wall passive subwoofer

🧾 Overview

The KEF Ci250RRb-THX is a high-output in-ceiling architectural subwoofer from KEF’s Extreme Home Theatre line, built to deliver deep, cinema-grade bass while staying visually discreet. Designed to be driven by the DSP-equipped KEF KASA500 amplifier, it reaches into truly low frequencies for movies, music, and gaming without a floor-standing subwoofer taking over the room.

✅ Key Features

✅ Deep bass extension down to 20 Hz (±6 dB, KASA setting) for true cinematic impact

✅ Extra-long-throw 250 mm (10 in.) bass driver with a massive 150 oz magnet for high output and low distortion

✅ THX performance: THX Certified Ultra with four Ci250RRb-THX on one KASA500; THX Certified Select with two

✅ High output capability up to 109 dB max SPL for large rooms and demanding content

✅ Ultra-Thin Bezel (UTB) design with paintable magnetic grille for an “almost invisible” install

✅ IP64 rated for dust protection and splash resistance (ideal for demanding architectural environments)

✅ Optimised for clean integration with AVR/processor bass management via KASA500 DSP control

📦 What’s in the Box

📦 KEF Ci250RRb-THX in-ceiling subwoofer (with Ultra-Thin Bezel design)

🧲 Paintable magnetic grille

📖 Documentation (installation / product documentation)

🔄 Compatibility

Designed to work with the KEF KASA500 DSP amplifier (recommended) and integrate into home theatre systems via standard AVR/processor bass management. Ideal for premium architectural cinema builds and pairs naturally with KEF Ci Extreme / THX architectural speakers. Suitable for dust-prone and splash-prone installation environments thanks to IP64 compliance.

📦✈️ Shipping & Returns

📦 Insured worldwide delivery

🔄 14-day return policy

🛡️ 2-year EU warranty

📝 Reviews

“accurate and powerful bass while remaining visually discreet” — Sound & Vision

“engineered to deliver incredibly accurate and powerful bass… (with) exceptional depth” — Audioholics

“capable of ‘accurate and powerful’ bass in large cinema rooms” — Home Theater Forum

⚠️ Warning

⚠️ Warning: Installing this sub may cause sudden “temporary ceiling acoustics expertise,” compulsive DSP tweaking, and an uncontrollable urge to add three more for THX Ultra. You have been warned.