KEF Reference 18" Subwoofer

If you want a home entertainment subwoofer that delivers apocalyptic bass extension with zero distortion, consider Model 209. Powered by a 1000W amp with DSP-based equalization and volume, phase, polarity and crossover parameters adjustable by remote control, the 450mm (18in.) cone has a double radial magnet, a unique dual suspension system, and the effective cabinet volume is virtually doubled by KEF’s Acoustic Compliance Enhancement (ACE) technology.

Uni-Q®

• KEF’s latest Uni-Q driver array is the most natural-sounding yet. The tweeter at the centre of the midrange cone now has a vented three-magnet motor system and a unique new braced dome, creating a perfectly time-aligned point source whose directivity is optimized by the re-profiled cone. As a result, dispersion is wider than ever. Power response is more uniform. Multi-channel imaging is even more stable - and stunningly realistic.

Cabinet

• Precision engineered to eliminate every unwanted vibration, Reference Series cabinets are works of art in themselves. Massive internal bracing tailors the volume of each enclosure to the exact parameters of its drive unit. Extensive mechanical and acoustic damping, together with independent driver loading and KEF’s decoupling techniques, creates inert enclosures that eradicate any vestigial panel resonance, standing waves, stray reflections or box colorations.

Crossover

• The Reference Series crossovers are computer modeled to optimize driver integration and response accuracy, and then fine-tuned by ear to ensure naturalness and a musically rewarding listening experience. Separate circuit boards are used wherever possible for the different frequency bands, with all components carefully laid out to minimize electro-magnetic interactions, and all boards are mechanically decoupled to isolate them from cabinet vibration. The quality of the signal path is maintained by taking advantage of the minimal losses in polypropylene capacitors and the linearity of air-cored inductors and the internal cabling is chosen for its accurate, neutral sonic character.

Faraday Rings

• KEF engineers have succeeded in greatly reducing the distortions that affect moving coil drive units by adding twin, balanced, Faraday rings above and below the voice coil. The negative effects caused by flux modulation and the variation of coil inductance with position are virtually eliminated by these carefully designed, low impedance ‘shorted turns’. By generating a magnetic field that cancels the unwanted field from the voice coil, this innovation reduces harmonic distortion by as much as ten times (20dB). Extending the benefits still further is the physical presence of the metal rings aids heat dissipation over the whole length of the voice coil, thereby improving the dynamic performance and power handling.

Finishes

• Piano Black, High Gloss American Walnut, High Gloss Cherry, Satin Black, Satin American Walnut, Satin Cherry and Satin Sycamore real wood veneers