KEF Aims High With $2,500 5.1.2 XIO Soundbar

KEF's First Soundbar?!?

KEF has announced the imminent launch of XIO ($2,500), the company’s first soundbar. Aimed squarely at the premium end of the market, the XIO is a 5.1.2-channel soundbar with support for Dolby Atmos, DTS:X, and Sony 360 Reality Audio. It is destined to compete with the best soundbars on the market, such as Sennheiser's AMBEO Max ($2,500) and the Devialet Dione ($2,200).

It is somewhat surprising that KEF has not created a soundbar before now, especially when we consider that the company was among the first traditional Hi-Fi speaker manufacturers in Britain to embrace surround sound in the early days of home theater, in the 1990s. KEF has long produced passive 3-channel LCR speakers for the front stage of typical living-room home theaters, and in more recent years has had considerable success with its active streaming speakers, such as the LS50 Wireless, LSX, and LS60. It was, perhaps, only a matter of time until the company would combine all of these ingredients into an all-in-one soundbar device. The XIO borrows KEF’s W2 wireless platform from the company’s existing wireless speakers, providing access to Tidal Connect, Qobuz Connect, Spotify Connect, and a number of other streaming services baked into the app, including Deezer and Amazon Music. In addition to the WiFi connectivity that enables AirPlay 2 and Google Cast, the XIO can accept audio via Bluetooth, HDMI eARC, and optical Toslink.

The XIO’s 5.1.2-channel system is powered by 12 Class-D amplifiers, which drive a number of custom-designed transducers. There are six Uni-Q MX driver arrays, of which only five are in use at any given time (depending on the physical orientation of the soundbar). Three of these fire forward for the LCR front stage, and two are aimed at the ceiling for height effects. There are four race-track-shaped bass drivers for the low frequencies, and a pair of 2-inch side-firing full-range drivers meant to increase immersion and provide surround-channel content. The XIO can be wall-mounted below your TV, or it can sit flat on a TV stand or other piece of furniture. When wall-mounted, the drivers that normally fire forward are pointed upward, and the ones that normally point up are pointed straight at the listener. KEF’s Intelligent Placement Technology (IPT) detects the soundbar’s orientation and automatically re-routes the correct signals to the drivers. Built-in microphones enable IPT to further adjust the XIO’s performance based on the listening space, detecting walls and furniture, and self-calibrating the audio automatically. For those who may struggle to understand dialogue, the XIO offers a dedicated Dialogue Mode, in addition to other EQ presets, such as Night Mode and Music Mode. All of the aforementioned smart features are part of KEF’s Music Integrity Engine (MIE) for Cinema, a suite of sophisticated DSP algorithms designed in-house for the XIO. The MIE also handles multi-channel processing and virtualization.

KEF XIO Driver Technology

As you might expect from KEF, all of the drivers used in the XIO were built from the ground up. The Uni-Q MX drivers used for the LCR and height channels function like miniaturized versions of KEF’s iconic Uni-Q coaxial drivers, but they are constructed rather differently. The regular Uni-Q comprises two separate drive units that fit into a single assembly, but they are distinct drivers that receive distinct signals from the crossover. The newly-developed Uni-Q MX driver is a dual-diaphragm design that includes its own mechanical crossover, which allows the central high-frequency diaphragm to operate separately from the midrange diaphragm. This decoupler separates the low-frequency cone and high-frequency tweeter dome, allowing the diaphragm to move freely at low frequencies while isolating the dome for high-frequency precision, according to KEF.

The bass is handled by two pairs of KEF’s newly-developed P185 LF drivers, positioned back-to-back in a force-cancelling configuration that significantly reduces mechanical vibrations, according to KEF. The racetrack-shaped P185 measures about 7 inches wide and 2 inches tall. According to KEF, the P185 has about the same radiating area as a traditional 4-inch circular cone, but its elongated shape allows the XIO to be considerably slimmer than it would be using more conventional bass drivers. The surround of the P185 incorporates KEF’s P-Flex technology, adapted from the KC62 and KC92 subwoofers. This tech reportedly resists acoustic pressure within the cabinet, enabling the driver to move with greater precision and to achieve deeper bass extension without sacrificing clarity.

Also at work inside the P185 LF drivers is a new patent-pending technology that KEF calls Velocity Control Technology (VECO). A built-in sensor within the bass driver monitors coil motion in real-time, employing a negative feedback loop to dramatically minimize distortion and compression, according to KEF. This reportedly delivers “ultra-clean, deep bass and a listening experience free from unwanted artifacts.” The embedded electromagnetic sensor within the driver features a sophisticated wire pattern that generates an electrical signal based on the speed of the voice coil. Surrounded by a magnetic circuit of tiny magnets and steel rings, the sensor is said to detect motion with “incredible accuracy,” inducing a current in response. This real-time data is then sent back into the amplifier through a negative feedback loop, correcting any misalignment between the audio signal and the driver’s motion, according to KEF. By applying the necessary damping to maintain system stability, VECO reportedly ensures that the signal reaching the driver’s voice coil is “a seamless integration of the intended musical content and real-time corrections.”

Even with all of this proprietary technology, there is only so much bass that four small drivers in a jam-packed chassis can create. Fortunately, users can add the subwoofer of their choice to the XIO, either by using the RCA sub output located on the back of the soundbar, or by using KEF’s KW2 RX Receiver ($160), which allows for the easy, cable-free addition of a compatible subwoofer, such as KEF’s KC62 or KC92.

While stereo speakers, such as the LS Wireless Collection, offer superior sound quality for music listening due to their larger drivers and left/right separation, soundbars excel in simplicity and convenience. With just one box and a single HDMI cable, setting up a soundbar is a hassle-free solution, making it an ideal choice for those seeking an immersive audio experience without the complexity of multiple wires. Soundbars also support advanced audio formats like Dolby and DTS, providing a cinematic experience that stereo systems may not easily match. For users who prioritize ease of use and space-saving design, a soundbar delivers high-quality audio with minimal fuss.

— KEF

KEF XIO Soundbar: Potential Downsides

The XIO is by all accounts an impressive soundbar, and early reports suggest that its performance is top-notch. But it’s not perfect. The biggest omission is probably the lack of dedicated HDMI inputs. The only HDMI connectivity onboard is the single HDMI eARC input, meaning all source devices, such as Blu-ray players, streaming devices, and gaming consoles, must be connected to the TV directly. The user must rely on the TV, rather than the XIO, to switch sources. Many competing products allow the user to connect source devices to dedicated HDMI inputs, as you would on an AVR. For example, the Sennheiser AMBEO Max has three HDMI inputs. The other limitation that stands out on paper is that, at launch, there is no way to add separate surround speakers, as you can with many other premium soundbars, such as the Sonos Arc Ultra ($1,000) or Bluesound PULSE SOUNDBAR+ ($1,150). However, KEF has announced that “an additional wireless surround feature with KEF wireless speakers” will become available in autumn of 2025.

The KEF XIO Soundbar is available in Slate Black and Silver Grey, with an aluminum top plate and “splash-proof” fabric completing its very attractive design. It should be available to purchase by the time you read this.

More information: KEF XIO Soundbar

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.