KEF Muo Bluetooth Speaker: Portable Hi-Fi

Impressive audio, with tight, controlled bass. Beautifully made aluminum body. 24-hour battery. USB-C audio makes it a great hi-res desk speaker too. IP67 rating. Bluetooth 5.4 with aptX Adaptive and Auracast support.

Minimal app controls. Auracast compatibility remains limited. No Wi-Fi.

The original KEF Muo launched back in 2015 and felt like a turning point in portable hi-fi. Serious, designer Bluetooth speakers from a respected hi-fi brand were rare back then—with only a few brands like Bang & Olufsen and Loewe interested in combining pretty and portable. These early designs were still given the side-eye by most traditional audio. At the time I was impressed by the sound of the original Muo and horrified by the price.

Fast-forward to 2025 and the portable speaker landscape is almost unrecognisable: There are superb portable speakers from the likes of JBL, and Ultimate Ears at a fraction of the cost, plus countless cheap options that still impress.

Coming in at $100 more expensive than WIRED’s favorite Bluetooth speaker, the JBL Flip 7, the new KEF Muo had its work cut out, but after living with it for a month, I’m starting to appreciate where the extra investment goes.

Flawless Looks

The Muo’s aluminum chassis is a flawless, curved triangular prism. The join-free tubing is impressively machined, and the grille design—inspired by the totemic $225,000 KEF Muon speakers, to give you an idea of the high end of this brand—draws the eye nicely. Measuring 8.5 × 3.2 × 2.3 inches, and weighing 1.6 lb, it is a little heavier than the competition, but has a typical Bluetooth speaker form factor.

This is a speaker you can tune to your outfit. I received “Moss Green” and “Orange Moon” samples for review, but there’s also “Silver Dusk”, “Amber Haze”, “Blue Aura”, “Cocoa Brown” and “Midnight Black”. Given the pricing, I think a case or travel bag should have been included, but it’s not a deal breaker.

The KEF Muo can be positioned vertically or horizontally, there’s knobbly rubber feet on the horizontal, and you get removable carrying strap. In truth, I wasn’t fully blown away by the design, partly because I expect a high level of finish on a premium product, partly because there’s some gorgeous alternatives out there, but mostly because it’s almost identical to the original. Back in 2015 having a designer like Ross Lovegrove involved caught headlines outside hi-fi circles, these days it’s almost de rigueur.

Gone are the original’s clicky buttons, replaced by modern sealed casing and indented controls. This has obviously helped KEF earn the IP67 rating, which means proper dust protection and the ability to survive a quick dunking. The new buttons do take some pressing, though.

Aesthetically the Muo remains stuck in 2015, but connectivity is bang up to date. Bluetooth 5.4 is paired with aptX Adaptive for near CD quality streaming (plus AAC and SBC), and there is Auracast support for broadcasting to multiple compatible speakers, opening things up for multi-room listening. There’s also Google Fast Pair and Microsoft Swift Pair for one-press connection.

And when you want to avoid lossy Bluetooth, the Muo’s USB-C port can also carry audio. Plug it into a computer (or portable media player), hold and press a couple of buttons, and it works as a 24-bit/48 kHz external speaker (depending on compatibility). There is no 3.5 mm aux input, but the USB-C digital connection covers most use cases.

In True Wireless Stereo mode (TWS), two speakers can be paired as a left and right stereo set, widening the soundstage. Stereo pairing, like USB-C, involves a few coordinated button presses, but remained stable throughout my testing.

Battery life is great, with up to 24 hours playback on one charge. You can top up three hours in just 15 minutes, and it takes two hours to full charge. It’s up there with the best alternatives, and means you’ll rarely need to worry about it.

Racetrack Driver

At the heart of the KEF Muo rebuild is a new racetrack-shaped mid/bass driver (2.5 × 5 inches) that has been paired with a 0.74 inch (19mm) tweeter and driven by a total of 40 watts of Class D amplification (30 watts for lows, 10 watts for highs.) The elongated oval shape (hence why they call these “racetrack” drivers) allows for more internal volume and greater efficiency. Combined with KEF’s own P-Flex Surround technology—a pleated structure borrowed from their subwoofers that reduces internal air pressure—it should get deeper, more controlled bass despite the tiny enclosure size.

The Muo even drew praise from airport security. On a recent trip, my bag was singled out for searching, and the officer asked me, “do you have an expensive Bluetooth speaker?” He explained that larger air volumes show up denser on X-ray. Cheap speakers, he said, rarely get flagged. It is a throwaway anecdote, but it neatly underlines what KEF is chasing here: more usable air inside a small enclosure, and the fuller sound that comes with it.

True to the press release, the Muo’s lower frequencies do have more about them than I expected, echoing quality hi-fi speaker bass, rather than the over-tuned sound of most portable speakers. It’s deeper and more immediate but also nicely controlled. There is heft, but it doesn't swallow the midrange as so many do.

Settling In

On first listen I was not blown away by the Muo. Much like Low-era Bowie, I have eventually grown to love it. I think the general quality of Bluetooth speakers has improved so much in recent years, that it’s easy to forget just how bad they can and did sound in the past.

KEF recommend giving the Muo at least a 10-hour run-in period, much in the same way you would break in the surrounds on a serious pair of Hi-Fi speakers. True to their word, and after a night of running in, the Muo started to sound less like a Bluetooth speaker, and more like a compact hi-fi component.

Across some bombastic classical, and my usual mix of MF Doom, Waxahatchee, and Neil Young using Quobuz and Spotify from iOS devices and a Windows laptop, the Muo remains impressively composed. Definition between bass, mids, and highs gives your music the chance to breathe, while the balance avoids the hyped low-end tuning that tends to dominate Bluetooth speakers.

Turned up loud, I heard no obvious distortion, and it remained a more comfortable listen at volume than cheaper rivals. That doesn’t mean I think small speakers should ever be cranked up to 11, but if you do insist on partying with it, you won’t be left wincing.

Stereo pairing is also genuinely effective. Two Muo speakers widen the stage, sharpen left-right placement, and make the whole thing feel closer to a small hi-fi setup than I expected. It also highlighted just how important the speaker’s run-in period is to the audio quality. I only tried pairing my review samples after about a week of solo speaker listening, and the difference difference between it and the boxfresh speaker was oddly stark.

Stereo pairing is a great addition here, but if you are about to spend $500-plus on two portables mainly for home listening, you should ask yourself whether a dedicated two-speaker system would serve you better.

Fierce Competition

You do not need to spend $250 to get excellent portable sound today. The JBL Flip 7 is $100 cheaper and remains WIRED’s favourite overall choice, and the Bose SoundLink collection has some bargains these days. Many alternative designs come with big batteries, booming bass, party-starting volume and extensive companion apps. But they can lack the same finesse.

At the premium end, pickings are slimmer, but the new Bang & Olufsen Beosound A1 reeks of designer charm and audio presence. The $329 Bose SoundLink Max is larger, but comes highly recommended as does the Sonos Roam 2. At $249 I think KEF has hit a bit of a sweetspot. It’s not much more expensive than the latest mass-market rubberized party speakers, but has premium build quality, impressive performance, extensive future-proof connectivity and Hi-Fi charm.

Run the KEF Muo in properly and you will be rewarded with a high-class Bluetooth speaker that bridges the gap between luxury design and affordability. The speaker has heft and class, with a flawless aluminium casing, and on-trend colorways.

It’s lacking Wi-Fi, the app is a little basic by 2025 standards, and I can’t help but feel like a design refresh might have given it fresh appeal, but these are minor gripes. I will admit, despite my worldweariness to it, Ross Lovegrove’s design still stands out.

At $249, it isn’t ‘cheap’ by any means, but if you want a portable speaker that behaves more like a mini hi-fi component rather than a pool party bass cannon, the Muo makes a strong case. With a 24-hour battery and IP67 it is ready for adventure, but it will be at its happiest entertaining you at your desk, without fuss or clutter.