KEF Reference 8b Subwoofer

About The KEF Reference 8b Subwoofer

To experience the full impact of dramatic on-screen effects in a home theatre system, bass precision and control are as important as its extension. You want powerful and articulate, not vague or smudged. That's why the Reference 8b subwoofer boasts two 500W Class D amplifiers, each driving a 229mm (9”) long-throw, ultra-low distortion driver. 

Using KEF's ingenious force-cancelling technology, these formidably powerful drive units are connected back-to-back in the heavily braced, acoustically inert cabinet. By cancelling out the forces they generate, this configuration allows both driver units to operate more effectively, giving noticeably greater definition to low frequency effects. If you have not experienced a truly great subwoofer, you will be amazed what a difference it makes to your viewing and listening pleasure.

Distortion-Free Depth: The Reference 8b features two 9-inch (229mm) drivers. Their hybrid structure, with a shallow, concave aluminium skin atop a paper cone, boasts a substantial motor system and a vented design in the voice coil. This design achieves linearity and vanishingly low distortion, ensuring every detail is uncovered regardless of volume. With optimised excursion characteristics, the Reference 8b achieves depths of 18Hz with fluidity and scale.

Power and Precision in Tandem: The two drivers in the Reference 8b are positioned back-to-back in a force-cancelling configuration. This design neutralises out reactive forces, minimising cabinet vibration and maximising accuracy and detail. This ingenious configuration enables an immense volume capacity, facilitating sound pressure levels of 110 dB from a relatively compact, sealed cabinet – a perfect balance of form and function.

Turn Up The Power: In a subwoofer, power goes beyond mere volume. The Reference 8b possesses immense power that fills almost any domestic space, with audiophile-quality 1000W of Class D amplification (a dedicated 500W amplifier for each driver). With great power comes incredible control, improving timing accuracy and dynamic response for a more detailed sound and the ability to deliver sudden bursts of power precisely when needed.

Well Connected: With a range of connection options, the Reference 8b adapts effortlessly to almost any audio system. Featuring RCA and XLR line level inputs as well as high-level speaker level inputs, it can be connected to any amplifier. It also has a Link Out to enable you to expand your system at any time.  

Comprehensive Subwoofer Settings: Most subwoofers have volume, phase and crossover selection and that’s pretty much it. Not so the Reference 8b. Its back panel has a veritable plethora of options to help fine tune the subwoofer to your room and system. These include Low Pass Mode (with Presets for KEF’s Reference series speakers), Low Frequency Level, Polarity, Room Position EQ, Crossover Frequency and Low Pass Filter Slope. Hours of fun for the whole family.

Total Attention To Detail: Every speaker in The Reference range exudes the sense of sheer quality that comes from being hand-built by KEF’s master craftsmen in Maidstone, Kent, UK. The expertly engineered cabinet of the Reference 8b is finished in a sumptuous high-gloss piano black which exudes sophistication and elegance.  

Our Review

If you’re after bass that’s not just loud but beautifully controlled and staggeringly deep, the KEF Reference 8b subwoofer is something rather special. This compact beast packs a whopping 1000W of Class D power - 500W per driver - delivered with surgical precision rather than brute force. The dual 9-inch drivers, mounted in a clever force-cancelling layout, produce thunderous lows without shaking the cabinet to bits, keeping everything tight and articulate. It digs right down to 18Hz with startling clarity, uncovering low-end detail you probably didn’t even know was there. With its glossy finish and superb build quality - hand-assembled in Kent, no less - it’s as refined to look at as it is to listen to. And with more tuning options than most AV receivers, it’s a proper treat for the tweakers among us.

Main Feature & Specifications

• Design: High Performance Powered Subwoofer
• Acoustic Design: Force Cancelling
• Drive Units: 2 x 9” (229mm) Drivers
• Frequency Range: Free Field: 18Hz (-6dB)
• Frequency Response: 24Hz at 90dB output in free-space mode (±3dB)
• Max Output: 110dB
• Amplifier Type: Class D with Switched Mode Power Supply and DSP Based Control Section
• Amplifier Power: 1,000 Watts RMS (2 x 500W RMS)
• Variable Low Pass Filter
  • Variable Frequency: 40Hz to 160Hz
  • Variable Slope: 12dB/oct, 18dB/oct, 24dB/oct
  • LFE Mode: 350Hz, 18dB/oct
• Inputs
  • Low Level RCA
  • Low Level XLR
  • High Level Speaker
• Link Output: Low Level RCA
• Power Requirements: 100 - 240 V ~ 50/60 Hz
• Power Consumption
  • 1,000W (operating power)
  • <0.5W (standby power)
• Removable Power Cable: Upgrade to a Premium Power Cable for better performance
• Finish: High Gloss Piano Black
• Dimensions (WxHxD): 365 x 398 x 429mm
• Weight: 34 kg
• Manufacturer’s Warranty: 5 Years + 1 Extended Year when Registered at KEF.com

Note: Features & Specifications Subject To Change Without Notice. E&OE.