PRICE $2500

AT A GLANCE

Plus

An impressive one-piece home theater solution

Setup requires little space

Excellent sound

Minus

Pricey

THE VERDICT

A premium soundbar has become an intriguing option for audio enthusiasts who can’t afford the space-hogging and/or budget-busting required for a complex and fully discrete home theater installation. The KEF XIO’s striking performance will surprise many dedicated and hard-to-please audiophiles.

The concept of home theater began before the year 2000. While the audio components needed to make the idea work could initially be cobbled together from parts originally designed for traditional two-channel audio, the video side remained woefully behind. Yes, there were interesting developments in that direction, notably by Henry Kloss and his NovaBeam video projector. But for the most part home video for the masses was largely achieved via, at best, 36″ CRT, tube-based televisions. Rear-projection televisions soon followed (clearly inspired by Kloss’s work). While they offered sizes up to 65″, they typically weighed in at 200–300lb! Top quality projectors serving even larger screens were pricey at the time, but even now that option remains out of the financial reach of most buyers.

But it wasn’t long before flat screen TVs revolutionized the market. They were expensive at first but over time became, as they are now, surprisingly affordable. There remained, however, one significant shortcoming of flat screen TVs: they’ve never won any prizes for sound quality. There’s simply too little space inside the chassis of a flat screen set, at least in the most popular sizes, for decent audio. Nor did it help that in the race for ever lower flat screen prices something had to give, and that something was audio quality.

The following sequence of events might come straight from my imagination, but makes for a convincing argument. It wasn’t long before enterprising manufacturers had their Eureka moments. They couldn’t improve TV sound very much without raising TV prices (a dead end for sales) so they invented the soundbar, a separately purchased device that could improve a TV’s audio quality. Most TV viewers will suffer through abysmal TV sound as long as they can hear the dialog, but there are enough buyers who’ll gladly drop $50 (or even $150) to improve their TV’s annoying sound—if only by a little. So the soundbar was born, and cheap versions remain widely available.

Enter home theater. For the true theater experience there’s no substitute for a big, multichannel home theater system. Those who want no compromises will continue to demand the best such setup they can afford. But to attract folks who don’t want the space hogging and budget busting demands of that full home theater route, the modest soundbar soon morphed yet again; the premium soundbar was born. AV manufacturers have jumped with both feet into that market. Such soundbars are now challenging the performance available from a full-up, multi-loudspeaker home theater installation, and doing so at a fraction of the complexity, cost, and often domestic disruption demanded by that traditional setup. Can even a super-sophisticated, premium soundbar fully duplicate the experience offered by a home theater installation costing five times as much and turning your media room into Mann’s Chinese Theater? Of course not; let’s get real. But you might be astonished at how closely today’s top soundbars can approach that ideal. Among them, the new KEF XIO (pronounced “zee-oh”) is, at a few pennies shy of $2500, one of the most ambitious.

If you’re unfamiliar with KEF, it’s a long-established and widely respected United Kingdom–based audio company. Most of its extensive offerings have been, and continue to be, loudspeakers (both powered and passive). They’re aimed at the serious audiophile. KEF’s highest end products are designed and built in the UK, but their other offerings are UK-designed but built in Asia. The XIO is manufactured in China.

Design

The XIO is KEF’s first Atmos soundbar. It measures 48″ by 6.5″ by 2.8″. The 6.5″ dimension is the height if the soundbar is wall mounted, either below or above the TV. Mounting brackets with concrete block wall screws and a helpful setup template are included. Alternatively, if the soundbar is laid flat on a TV table in front of the TV, the 6.5″ dimension is now the depth of the soundbar and the 2.8″ measurement is now the height.

Wait—what? How can that be? Using built-in sensors, the soundbar recognizes how it’s oriented (on a shelf or wall-mounted) and automatically adjusts both its EQ and internal channel routing, so drivers that handle the front left/right channels in one orientation can be reassigned as the upfiring Atmos drivers in another. I used it in the 6.5-inch vertical-front orientation for all of my listening. (To hopefully minimize confusion here, when needed I’ll refer to the 6.5″, forward-facing configuration as the wall-mount setup, even though I didn’t actually mount the soundbar on my wall: I used shims to keep it in proper position.) If the KEF XIO ends up as your soundbar, I recommend trying both setups to determine your preference before drilling holes in your wall! (Other reports I’ve seen suggest that the 6.5″ vertical dimension sounds marginally better, though the differences may be subtle.)

The XIO is wrapped in cloth in the buyer’s choice of Silver Grey or Slate Black. There’s a range of recessed inputs and outputs on the panel, including power on/off, Service, TV (eARC), Optical, Network, and an RCA Subwoofer output. I didn’t use the Service or Optical connections. One oddity here is that when you look at this connection panel while standing at the front (as you would in the wall-mount setup) and look down at these connections, all of their labels appear upside down! Awkward, but likely an unavoidable result of the XIO’s two possible setup orientations.

The XIO can properly play back any flavor of film sound, from compressed to high definition and including all widely used surround sound formats. In Dolby Atmos–speak, it’s a 5.1.2 playback configuration. That simply means its goal is to duplicate the experience you’d hear if discrete loudspeakers were actually positioned around the room rather than fitted into a relatively small box as they are here. To achieve this a total of twelve individual loudspeaker drivers populate the inside of the enclosure. Six of these handle the midrange and highs, each of them a small version of KEF’s widely used Uni-Q loudspeaker technology (dubbed here as Uni-Q MX). Most full-sized Uni-Q drivers employ a woofer (usually 5.5″ in diameter or larger) and a tweeter, the latter nestled at the apex of the woofer’s cone (technically known as a coincident configuration). In the XIO soundbar, however, each of these Uni-Q loudspeakers is a smaller version that here covers only the midrange and highs. All of the XIO’s bass chores are handled by four rectangular woofers, and two additional, full-range drivers are reserved for surround effects. Each of these twelve separate loudspeakers is driven by its own class-D amplifier.

Unlike some soundbars, the KEF is self-contained. That is, it doesn’t include, nor offer, a pair of the small, self-powered surround speakers positioned elsewhere in the room to enhance rear and/or overhead effects. This choice avoids clutter and the cost this would add to what is already one of the pricier soundbars on the market. The company says wireless rear functionality is actively being worked on as a feature. KEF does offer an optional selection of suitable powered subwoofers, both wired and wireless. The XIO can also be used with other subwoofer brands as well via its RCA subwoofer output. I didn’t use any external subwoofers for this review, relying exclusively on the four racetrack-style oval woofers inside the KEF’s enclosure to support the bottom octaves.

The front panel of the XIO (again, the front as viewed in its wall-mount configuration) also includes a range of soft-touch buttons for a few selections such as on/off and volume, plus a string of LED lights that indicate if the soundbar is on or off (it also plays a subtle little tune when fired up or shut down!). I didn’t find the LED lights particularly readable in showing the volume level.

Features

Once the XIO is set up you won’t often use its on-chassis adjustments. There are two other, easier ways to control it: a supplied remote control and the KEF Connect App, the latter downloadable onto your Apple or Android phone. You’ll definitely want to download this App; it offers access to a far wider range of control than either the soundbar’s chassis itself or the supplied remote control.

The XIO is loaded with unusual features. The first is Intelligent Placement Technology, or IPT. When you select this feature on the App the XIO emits a few test tones. The XIO then uses this result to analyze how the XIO’s in-room location is affecting the sound at the XIO’s specific location and corrects for it. For example, if there’s a wall or other large obstacle just a foot or two from the left side of the XIO but open space on the right. Yes, you should avoid such odd placements, but if you can’t the IPT might help. IPT is not, however, the same thing as complex room-correction programs such as Audyssey or Dirac Live, which can compensate for sonic errors experienced at the listener’s position in the room (and, at best, for other nearby listening seats). The XIO’s IPT feature can’t do that. (Neither Audyssey nor Dirac Live is usable on the XIO.)

Two other important performance features on the XIO are Velocity Control Technology (VECO) and Music Integrity Engine (MIE). VECO uses motion sensing together with a feedback loop to limit distortion from the XIO’s relatively small woofers. KEF states that this reduces bass distortion (not bass output level!). The MIE uses DSP to connect all of the XIO’s parts into a cohesive whole. One aspect of this is dynamic correction. As I understand the latter, it involves dynamic compression to keep the distortion below KEF’s desired level if the XIO is pushed to extremes by the source or (more likely!) by the listener.

The KEF Connect App offers a wider range of options than can be covered here in detail. Some are self-explanatory or become clear with use. I can’t make much sense of entries such as “Schedule-Sleep timer, Alarm.” Is that to wake you up to go to bed if you’ve fallen asleep watching a movie? But “Volume” alters the sensitivity of the steps on the volume control on the App (and on the remote control as well). A series of questions on the App may also be useful in optimizing the XIO’s performance, such as “How high is your soundbar?,” “How large is your room?” and “Do you have a subwoofer connected?” But the selection on the App that you’re most likely to access frequently is Sound Profile. There are several of them; I preferred “Movie” and (less often) “Music.” The remote provides direct access to two profiles, and the app not only lets you access additional profiles but also choose which two are bound to the remote’s profile buttons for quick access to your most-used settings.

Having an eARC HDMI connection on your TV is important for achieving the XIO’s best performance. Older TVs might offer simply an ARC input (without the “e” prefix). This will limit the bit-depth resolution the XIO can deliver. If this is the case you might want to, at least, plan for a new TV, either now or later. (Just check first to insure that your choice of a new TV has at least one eARC input. Not all new TVs support eARC, though it’s becoming more common.)

The XIO is also a widely capable music streaming machine. There are nearly endless music sites it can access, ranging from high resolution to compressed, including Bluetooth. I’m not much of a music streamer, preferring to rely on my large collection of in house discs of all descriptions for both movies and music. I did stream lossy audio with video, both music and streamed movies, from my TV into the XIO with no issues. But all of the movies referenced below were sourced from high definition video discs.

Performance

I’d be overstating the case here if I claimed that the XIO (or for that matter any premier soundbar) can light up a room in all directions as well as a high performance, 5.1 or higher multichannel setup with physical loudspeakers in all the important locations. But can it come satisfyingly close? Yes, it can, and it did so for me.

Oblivion is easily my favorite science fiction film of recent decades, at least among those that don’t need one or more sequels for completion (hello, Dune and Lord of the Rings!). It’s also a spectacularly good Blu-ray, both visually and sonically, demanding playback gear that can take advantage of its sound-all-around mix. The XIO is extremely effective on that score. Its overall audio performance is superb, with clear, believable dialog, a sweeping music score, and convincing audio effects. Early on in this film Jack (the lead character) drops down into the dark, cavern-like wreckage of an old library. The sound here begins subtly, filling the room with the ambience needed to make the location convincing. But soon the basic ambience becomes the background for more overt details that jump out faster than I could precisely dwell on them—much as would occur in real life. After Jack narrowly avoids capture by unseen “aliens,” the action continues with even more convincing sonic detail. All of this adds to the story without distracting me from it. That’s the whole point of a good sound mix.

While this wasn’t a particularly challenging sonic event, due to the distance the characters supposedly are from the explosion in the story, it is convincing. The XIO’s overall sonic balance is never lacking, or at least doesn’t overtly remind me that a subwoofer would further enrich the experience. It sometimes surprises me in how well it handles the full audio range. While it won’t challenge a good subwoofer, the bass on this, and on even more challenging, low-end material in my large room, never leaves me feeling shortchanged. As ever, of course, the room itself and the XIO’s position in that room will play a major part in this.

Dune Part 2 is nearly as impressive. I say “nearly” only because it features long stretches with subtle or limited sound, sometimes accompanied only by the wind on the endless desert. But the ending, where Paul and his followers fight the emperor and his minions for control of Arrakis, is full-on climactic. I’ll go no further to avoid spoilers, but Dune fans won’t be disappointed when hearing this film (and Part 1) on the XIO.

The heaviest audio hitter of the films I sampled here, in its striking ambience and overt room expanding sound, is Mimic. Don’t go near this film if you’re squeamish. It’s about giant, mutated, hungry bugs living in dark, deep, and long-abandoned stretches of the New York subway system. Is the latter true (not the bugs but the ancient locations and equipment)? I don’t know, but the film would be creepy enough even without man-sized bugs. I had a late uncle who worked on the New York subways for 30 years and he never mentioned anything about these ancient bowels hidden below modern cars and subway stations. Could this be a closely guarded New York subway trade secret?

The sound mix here has a field day on the XIO. There’s so much surround activity that it’s hard to know where to begin. It starts slowly, explaining the process that led to those huge bugs. And as the main characters find themselves trapped deeply underground, there’s a dramatic wash of chilling sound all around you, first from the reverberation of newer subway cars and stations and later as the film’s characters fight for survival. It would be a rare viewer who could sit through two uninterrupted hours of this, but those who endure it will get an object lesson on how the XIO can convincingly deliver sound all around you in a way you never expected from a soundbar, even one as highly sophisticated as this one.

My listening position is roughly front and center. When I moved about 30 degrees to the left the overall audio balance is still impressive but the envelopment, particularly coming from the rear, fades noticeably. This is unavoidable when all of the audio is generated at the front. The front middle has long been called the Money Seat for a good reason; the same effect also occurs in two-channel audio, but in that situation mainly on the left-right balance.

Conclusion

The only significant issue I encountered involves selecting an optimum gain that works best for both dialog and the more aggressive action bits. On some material, if I set the dialog too sparingly the action audio is a little too tame. If I set the action bits as high as I want (without generating obvious distortion) the dialog is too hot. But I didn’t ponder this too deeply. I was having too much fun listening to the XIO. I do admit to riding the gain a bit, using the remote control to raise or lower the level by 2–3dB as needed.

That said, I can unequivocally recommend the XIO for the home theater enthusiast who can’t or won’t consider a room filled with A/V gear. And even those who can do so might just open their eyes to an option they’d never before considered.