The buzz may be about this new soundbar’s “wow factor” performance…but the unique tech inside is the real hero. Read on to discover how it works...
KEF have done it again.
Their new XIO Soundbar has brought a new level of performance into the world of minimalist home cinema. It's no surprise, either, considering KEF have been innovating since they were founded in 1961.
In the early days, founder Raymond Cooke shook the audio industry by inventing a new kind of speaker driver (that's the part that pushes the air). It was called the B139, and it delivered deeper and richer bass from a smaller package. This driver was commissioned by the BBC to fit their cramped recording vans with better monitors…and it spread like wildfire through audiophile communities around the world.
From there KEF continued to innovate, now having amassed more than 150 patents. And their latest creation—the KEF XIO Soundbar—is carrying the torch that much further.
KEF XIO’s unique tech allows it to overcome a fundamental problem faced by slim soundbar systems...
Which is good news, because it’s clear that the age of “big black box” hi-fi has passed. Most people simply prefer things a bit smaller, more minimalist, easier to manage, and less disruptive to the look of their homes.
Hence the ubiquitous rise of the soundbar form factor. However, despite the advancements that gave way to the soundbar, they rarely offer the kind of depth and clarity that’s possible with bigger systems.
Why? Well, the same reason soundbars are so great is also why they struggle to produce high-fidelity sound. Namely, their form factor: only very small speaker drivers can fit into the slim cabinet.
To understand why small drivers are a problem, consider a piece of string…
Imagine holding it at both ends, then trying to wiggle one side up and down. If you go fast—say, four times per second—you find the string appears to make a wave pattern. However if you try to wiggle slowly—only once per second—the string just droops, and one side moves lifelessly up and down.
This demonstrates resonance: a phenomenon which happens with all mechanical systems, including speaker drivers. Essentially, smaller drivers move less efficiently at lower frequencies than bigger ones. Thus, when you’re limited by the slim form factor of a soundbar, it’s harder to produce bass and lower midrange sounds—resulting in thin, lifeless sound.
Enter KEF’s specialty: they’ve been inventing driver technology since the day they were founded, and they never stopped.
The XIO features several innovations, including two proprietary driver designs that let it overcome the limitations of a slim soundbar enclosure—and deliver standout audio performance in its category.
First, the P185 “racetrack” driver, four of which handle the bass and lower midrange frequencies.
It’s a page right out of Ray Cooke’s playbook. The P185 has an ovoid shape that allows it to fit inside a slim enclosure, while producing deep bass tones and quality lower-mids. It’s the physical equivalent of a 10cm circular driver, but it fits within a 5cm space.
Plus, in addition to its effective size, the P185 features KEF’s “P-Flex” surround. This material gives the driver plenty of throw (the distance the driver can travel back and forth, which is crucial for producing bass) while having ridges that prevent it from deforming under pressure.
To top it off, KEF have applied what they call “VECO Technology” to the P185. This is a feedback system built on flexible circuit boards (so they can move with the driver) which monitors driver movement and constantly corrects the signal to remove distortion.
The result of this technology cocktail is impressive:
Even with no sub, the XIO has stunning bass extension and a rich, full-bodied lower midrange…despite a slim form factor.
Then there’s the Uni-Q MX, six of which handle the main channels in the XIO.
At first glance, it’s a smaller version of KEF’s famed Uni-Q driver. The high-frequency tweeter and midrange driver are mounted on the same axis; this allows a full range of sound to come from the same point in space. (It effectively allows two full-performance drivers to fit into a much smaller space.)
But the Uni-Q MX—found inside the XIO Soundbar—adds some unique tech into the mix. It features a mechanical crossover design, which lets the driver produce a wider range of frequencies without dulling the high-frequency response.
Here’s how it works: In the mids, both the tweeter dome and midrange cone move together. As the frequency rises, the drivers are decoupled and the tweeter and midrange operate independently, producing their respective frequency bands with greater clarity.
All up, these two brand-new driver designs have made the KEF XIO an exceptional performer in the popular soundbar arena.
To top it off, the XIO is the newest product to support KEF's proprietary wireless ecosystem.
I’m talking about wireless multi-room audio: the same product category that’s dominated by Sonos—among the most convenient and flexible listening systems available—except KEF is one of the first brands to bring true high-fidelity sound to the space with products like LS50 Wireless II and LSX II.
Many quality audio brands attempted to adopt the wireless multi-room approach, but found that developing the software ecosystem needed to pull it off was a costly challenge. There were a lot of failed product lines and abandoned systems.
KEF was one of the few that persisted through, eventually leading to their W2 wireless multi-room ecosystem. Once that software system was proven, they set their sights on their first multi-room home cinema system.
Which brings us back to the XIO. The XIO not only produces exceptional sound by defying the physical limitations that plague other soundbars…but it’s designed to be paired wirelessly with any of KEF’s LS speakers for full surround sound with minimal cables. [Note: This feature will be available via software update around October 2025.]
For instance, you can mount a KEF XIO Soundbar by the TV to deliver the left, right and centre channel audio—as well as the Dolby Atmos / DTS:X height channels—producing a massive soundstage with panning effects, punchy action, and clear dialogue.
Then [pending the software update] you’ll be able to place two KEF LSX II LT speakers at the back of the room, wirelessly enabled as surround speakers wrapping your ears in a complete soundscape.
And finally, you’ll be able to tether a KEF KC62 Subwoofer to the system wirelessly, to extend deep into the lower registers for full impact…giving you a complete Dolby Atmos / DTS:X surround sound system with exceptional detail and depth.
(Note that the XIO can provide a 5.1.2 channel experience on its own too—with side-firing drivers giving a sense of surround, up-firing height channels, and surprising bass extension to cover the lower registers.)
All up, the KEF XIO Soundbar brings innovations in exceptional sound quality and seamless minimalism into the home…
If you’d like to check it out, you can learn more about it here. If you’re in the Sydney area, you can visit our showroom in Leichhardt to hear it in full effect—we have it set up in one of our private listening rooms.
