KEF Blade Loudspeakers Review
For more than six decades, KEF (Kent Engineering and Foundry) has been applying innovative engineering to the speaker’s design.
In 2012, KEF introduced the KEF Blade, a full-range point source speaker system. It is a product of many years of research, analysis, and custom-made software and tests.
The KEF Blade look fantastic, and everyone that sees them has only compliments on the design, which resembles a knife blade. Although many years have passed since the Blade came out, it still looks futuristic.
- Fantastic design
- Rich and detailed sound
- Excellent imaging and wide soundstage
- Needs powerful amplifiers to perform best
The speaker looks like a statue with its 159 cm height and 54 cm depth. The weight is 57 kg, and you need effort and strength to put the speaker in position.
Each speaker has two pairs of side-firing 9-inch woofers and a 5-inch Uni-Q driver array responsible for the mids and highs.
Each of the four 9-inch drivers has vented couplers that allow the air behind the driver to escape easier, so the back-wave pressure reduces, and so does the distortion that could happen. The Force Canceling technology (the driver mounting is opposed back to back) helps eliminate the driver vibrations to transfer to the cabinet, so the sound’s clarity is better. Each driver pair is in a separate bass enclosure, so the internal standing waves are reduced.
The cabinet consists of a glass-reinforced composite material, rigid and inert but capable of being shaped. This material is responsible for the KEF Blade ability to be a single source where the sound from all the drivers sounds like coming from a single location.
KEF has spent more than 20 years improving the Uni-Q driver’s technology. The 1-inch dome tweeter with tangerine waveguide controls the beaming and increases the dispersion. Its shape matches the large voice coil 5-inch hybrid midrange driver within which it is mounted. The reason behind this is to remove the secondary radiation anomalies. The 5-inch diaphragm is a composite construction of lithium, magnesium, aluminum skin with a liquid crystal polymer skeleton. The midrange is also in a separate enclosure that is decoupled from the main cabinet.
The four bass drivers (230 mm) also have a radical design. Mounted on both sides in back-to-back pairs, the reaction forces of the drivers cancel each other. The woofers placed close to each other and to the Uni-Q driver align their acoustic midpoint.
The best components available are used in the crossover and carefully selected so that every part of the signal has the highest level of clarity. Crossover points are at 350 Hz and 2.3 kHz, and KEF recommends pairing the KEF Blade with amplifiers with power output between 50 and 400 watts per channel. The minimum impedance should be 3.2 ohms. The sensitivity rate is at 91 dB.
There are two sets of high-quality WBT terminals on the back of the cabinets that accept both bananas and fork terminals under screw-down posts. These two sets of terminals allow bi-wiring, and if you use only a single set of cables, jumpers are factory installed for extraordinary performance.
KEF supplies a footer kit with spikes for carpeting and flat discs for the tips if used on hardwood or another surface prone to scratching. A convenient round bubble level is in the plinth at the speaker’s back, which helps to see when the speaker is standing straight.
The KEF Blade delivers an impressive soundstage, and thanks to the off-axis imaging, there is less dependence on the sweet spot, so it doesn’t matter if the listener is in the center or sitting to the right or left.
Even when playing music loudly, when you touch the speakers, you don’t feel any vibrations, even at low frequencies like 28 Hz. The low end is deep, powerful, and well-timed, without any colorations.
Musically, KEF Blade reveal detail, and the bass line is tight, robust, and transparent. Imaging is pinpoint with instruments imaged in the middle, and to the right, background singers reflected on the left, and the singer in the center of the soundstage. The placement and location of instruments and voices in the sound field are fantastic.
The Blades depend on the room, and they sound their best in an ample space. So if you want to have the best results, you should place the Blades away from the walls. Stereo imaging is the most outstanding characteristic of the speakers.
What you get for the money you pay is one of the most beautiful speakers on the market. They don’t only look good, but the engineering behind them is extraordinary.
The KEF Blade are certainly not meant for a budget audio system, so when you pair them with electronics and cables of the same quality, you get an excellent speaker system.