Astell & Kern UW100 MKII review: insightful sound, cumbersome design

Astell & Kern is no amateur when it comes to sticking a premium price on a physically small product - its market-dominating range of digital audio players is testament to that. But when it comes to the best true wireless in-ear headphones, the company is up against stronger, and much more numerous, competition than it’s ever faced. So does this second-generation of the AK UW100 have what it takes to justify the asking price?

Astell & Kern UW100 MK2: Price & Availability

The Astell & Kern AK UW100MKII are on sale now, and in the United Kingdom they’re yours in exchange for £269. In the United States they’ll set you back $299 or so. While in Australia you’re looking at AU$499 or thereabouts.

For the sake of brevity I won’t list every alternative pair of true wireless in-ear headphones you can buy for very similar sort of money - but even if I just mention Apple, Bose, Sennheiser, Sony and Technics as examples, it’s obvious Astell & Kern has some stiff competition to see off if the AK UW100 MKII are going to make it onto your shortlist.  

Astell & Kern UW100 MK2 review: What's New?

With the AK UW100MKII, Astell & Kern has bet big on the ‘sound quality/audiophile’ side of things. So the headline features here are all about maximising playback.

Wireless connectivity is via Bluetooth 5.2, and there’s compatibility with SBC, AAC and aptX Adaptive codecs. Digital audio information is dealt with by an overspecified 32-bit AKM DAC chipset, before being served to your ears by a Knowles balanced armature driver in each earbud. Astell & Kern is too self-effacing to suggest the sort of frequency response this comprehensive specification might be capable of producing.

There’s no active noise-cancellation (ANC) here, though - and there’s no two ways about it, this is a strange omission for a product of this type selling for this sort of money. Astell & Kern can (and, indeed, does) bang on about the sort of passive noise-isolation that’s achievable when the earbuds are correctly fitted - and, up to a point, that’s true. But not only is a well-implemented active noise-cancellation system significantly better at keeping the sound of the outside world at bay, it’s also a specification box that every price-comparable rival ticks.    

Astell & Kern UW100 MK2 review: Performance

Yes, there are EQ settings to be investigated and DAC filters to explore - but the good news is this: it’s extremely difficult to make the Astell & Kern AK UW100MKII sound anything less than impressive.

There’s a lovely balance to the way they sound, no matter the sort of stuff you like to listen to or the quality of the digital file in which it’s transported. The overall tonality is convincingly neutral from the top of the frequency range to the bottom, and the UW100MKII create a nicely open, properly organised and easy-to-follow soundstage that gives every element of a recording more than enough space in which to express itself. And this is true no matter if you’re listening to a massed orchestra or demo-style voice-and-guitar.

The single-driver arrangement means the balance of the frequency range is just so, and the Astell & Kern are alert to even the finest details at every step. They have the sort of insight and dynamic potency to tease out the finest tonal and textural details less accomplished designs overlook, and they can put quite a distance between ‘gentle intro’ and ‘almighty final crescendo’. 

Control is good across the board, too. Low frequencies are properly shaped and snap, rather than slur, in and out of individual notes or hits - so momentum is high and rhythmic expression is confident. The top-end has a good amount of substance to balance the considerable bite treble sounds can summon, too. And in between, the Astell & Kern have ample insight across the midrange for a vocalist to manifest as much character and emotion as they’re able.

They’re a very composed listen, too. Quite a few alternative designs can fall to pieces, relatively speaking, at high volumes or lose some animation at low volumes, but the UW100MKII simply get quieter or louder without altering their characteristics in the slightest. As long as you’re listening in a fairly quiet environment (and there’s no guarantee of that, of course - these are the very definition of a portable product, after all), the Astell & Kern are as faithful and well-realised a listen as any price-comparable rival.  

Astell & Kern UW100 MK2 review: Design & Usability

It’s hard to blame Astell & Kern for wanting to exploit its established angular design language here, but insisting on an overt pentagonal finish on the outer surface of the UW100MKII has resulted in an earbud that’s larger (22 x 21 x 23mm) and heavier (7g) than the norm. 

Although the inner part of the earbud is more sensibly and ergonomically shaped, the Astell & Kern nevertheless feel big and relatively cumbersome once in situ. And getting them in situ is slightly more of a faff than it really should be - they’re almost comically difficult to prize from their charging case if you’ve fingers wider than cocktail sticks. 

The charging case, like the earbuds themselves, is built from unremarkable plastic - the outer surface of the earbuds tries to pretend it’s metal, but you only need touch it once to realise the truth.

Control is covered by the usual trio: voice-control via your source player’s native assistant; capacitive touch-surfaces; and an app that’s free for iOS and Android. The pair of mics in each earbud prove more than up to the task of dealing with voice control, just as they do with telephony.

The touch-surfaces are a slightly more qualified success. Despite the generous dimensions of the outer surface, a degree of precision is required to get what you want - again, the UW100MKII seem to have been designed for the tiny-fingered.

Available controls consist of ‘play/pause’, ‘skip forwards/backwards’, ‘answer/end/reject call’, ‘volume up/down’, ‘summon voice assistant’, and adjusting the amount of ambient sound you hear. Because although there’s no ANC here, Astell & Kern is more than happy to increase the amount of external noise you might want to hear. 

Some of these functions can be rearranged in the Astell & Kern Control app. It’s a stable, good-looking interface that’s slightly less use than it thinks it is. An indication of battery life is good, as is the 10-band equaliser with six presets. Four levels of ambient sound (five if you count the ‘off’ position) is useful up to a point. Having a choice of four DAC filters seems to be a gesture towards audiophile credibility - but if the UW100MKII had ANC the differences between them might be easier to discern. And having no playback controls at all is a definite omission, especially when the touch-surfaces aren’t as reliable as they might be. 

You’ll need to take a little more care about where you use these earbuds than you do with any of their nominal rivals, too. The Astell & Kern have no formal IP rating, so any even mildly adverse condition might be a disaster for the UW100MKII - who knows? Still, at least you’ve as much as nine hours of battery life from the earbuds if you can keep out of the rain for all that time - there are another couple of full charges in the case, and a 10-minute pit-stop should hold you for another hour or so. USB-C and wireless charging are supported.  

Verdict

For me, the accommodations you have to make in considering the AK UW100 MKII - where fit is concerned, where ergonomic shortcomings are concerned, where the lack of active noise-cancellation (ANC) is concerned - are probably too great. 

But the fact remains that if you want one of the best-sounding pairs of true wireless earbuds at this price, Astell & Kern does know how to make a strong case...

Also consider

The Bose QuietComfort Ultra Earbuds are the anti-Astell & Kern in some ways. Their active noise-cancellation is stupendous, their comfort is unarguable - and when it comes to sound, they’re on the coattails of the Astell & Kern too. 

Of if you don’t mind wearing what everyone else is wearing, you could do a lot worse than check out the Sony WF-1000XM5 - they’re not class-leading in any particular area, but as an overall package they’re mighty hard to argue with.