When KEF gave their engineers free rein to create the best speaker they could, they came up with the revolutionary Concept Blade prototype – the world’s first single apparent source loudspeaker. Its sonic capabilities were so impressive that KEF created an edition that serious audiophiles could actually own.
Sculptural and acoustically inert, the slender parabolic enclosures of the KEF BLADE loudspeakers are engineered never to interfere with the purity of the output. Inside, you find ingenious new venting, bracing and wave management technologies. Every component operates so comfortably within its performance envelope that you experience noticeably more precise imaging than is possible with conventional speakers.
Just as KEF’s philosophy has always been to innovate in pursuit of the most accurate and realistic sound, BLADE speakers are about perfecting a groundbreaking concept to delight people who really love music. Whatever your taste, KEF BLADE are what all great design aspires to: being the best they can possibly be.
Like listening to one voice rather than many, sound from a single source is inherently clearer. Not only are the acoustic centres of the HF and MF drivers in the KEF BLADE Uni-Q array coincident, but the four LF drivers, (225mm/9-in.) are mounted symmetrically equidistant from it so that their acoustic centres occupy exactly the same point in space.
This single apparent source configuration is what makes the KEF BLADE so gratifyingly coherent across the frequency range, with noticeably more precise imaging than is possible from any conventional speaker. What you hear sounds as if it’s being performed live right in front of you.
To avoid dissipating the energy of such potent bass drivers in exciting the cabinet (and thereby generating resonance, especially at high volume), the large kinetic forces involved are cancelled out by mounting the LF drivers rigidly together, back-to-back.
By minimising cabinet colouration, this highly effective configuration partly accounts for the KEF BLADE natural-sounding and engagingly musical performance.
The twinned pairs of bass drivers are mounted in discrete chambers separated by an internal partition. By increasing the frequency of any internal standing waves to way beyond the crossover point, this reduces the need for damping material (which can otherwise impair bass quality). Nothing has been overlooked in the quest for the ultimate clarity, right across the frequency range.
The patented screw-in linking plugs are to full audiophile specification (as well as simplifying set-up by eliminating fiddly wiring links). All the crossover components are individually wired by hand rather than mounted on a conventional printed circuit board. As well as being more environment-friendly, this optimises both reliability and sound quality by assuring the cleanest possible signal transmission.
Design – Three-way bass reflex, single apparent source driver configuration
Drive units – Uni-Q driver array: MF: 125mm (5in.) Li-Mg-Al /LCP hybrid cone, HF: 25mm (1in.) Al dome Bass units: LF: 4 x 225mm (9in.) with force cancelling
Frequency range free field (-6dB) – 28Hz – 45kHz
Frequency range typical in room bass response (-6dB) – 20Hz
Frequency Response (±3dB) – 40Hz – 35kHz ±3dB (-6dB at 28Hz)
Crossover frequency – 350Hz, 2.3kHz
Amplifier requirements – 50 – 400 W
Sensitivity (2.83V/1m) – 91dB
Harmonic distortion 2nd & 3rd harmonics (90dB, 1m) – 0.5% 40Hz – 100kHz, 0.2% 200Hz – 10kHz
Maximum output (peak sound pressure level at 1m with pink noise) – 117dB
Impedance – 4Ω (min. 3.2Ω)
Weight – 57.2 kg (126 lbs) each
Dimensions – with plinth (H x W x D) – 1590 x 363 x 540 mm