Astell & Kern AK UW100: Specifications

Colors: Black
Battery life: Up to 24 hours
Bluetooth 5.2 (codecs: SBC, AAC, aptX adaptive)
Water resistance:
0.25 ounce

Given its high-end reputation, the Astell & Kern AK UW100 is not outrageously priced and priced to meet recognized class leaders.

As the first pair of true wireless earbuds, on paper the AK Hi-Fi TWS UW100 (to give them their full name) are a mix of “great specs” and “notable spec omissions”. In practice, however, the sound they produce will be impressive enough that all but the most committed (or those for whom the negation of external sound is even more important than the quality of the sound they’re listening to) overlook these shortcomings. When it comes to direct sound quality, these Astell & Kern headphones are among the best true wireless designs on the market, at any price.

Astell & Kern AK UW100 review: Price and availability

The Astell & Kern AK Hi-Fi TWS UW100 (which we’ll now call “UW100” for everyone’s sanity) is on sale now, and it’s priced at $299 / £249.

You will need more than two hands to count all the many, many pairs of similarly priced, broadly specified and performing alternatives that exist at this kind of money. Everyone from Apple and Bose to Sennheiser and Sony, not to mention savants like Bowers & Wilkins and Grado, has a product in direct competition. It’s a bold or foolish move on the part of Astell & Kern – can you guess what it is?

Astell & Kern headphones in their case

(Image credit: Tom’s Guide)

Astell & Kern AK UW100 review: Design

Anyone familiar with Astell & Kern’s line of extraordinarily accomplished and deeply priced digital audio players will know that the company has a very specific design aesthetic. And just because true wireless earbuds are small and functional, A&K didn’t miss the chance to put its distinctive design stamp on the UW100. As much as possible, anyway.

A&K rolled out its familiar “light and shadow” angularity on the outer surface of the headphones and did something similar on the lid of their charging case. The result is a pair of headphones that look as individual as ever. They are also noticeably large and weigh 0.25 ounces (about 7g), a bit heavier than the standard.

Inside, the UW100s feature a high-resolution 32-bit AK4332 digital-to-analog converter and two high-end balanced armature drivers sourced from renowned Knowles experts. Each of these is louder than usual in products like this and (at the very least) indicates how serious Astell & Kern is when it comes to audio quality.

Although it would seem – on paper, at least – to be a little less serious about banishing external influences on this audio quality. The UW100 lacks active noise cancellation (which is included in virtually all comparably priced competitors) – instead the company makes bold claims about the effectiveness of the passive noise isolation provided by the comfortable nature of how the headphones fit…

Headphones on a colored surface

(Image credit: Tom’s Guide)

Astell & Kern AK UW100 review: Comfort and fit

Despite their relative size, the UW100s are very comfortable to wear and secure in situ. Part of that is down to the “twist-and-lock” positioning method that’s familiar to any earbud that doesn’t ape Apple, and part is down to the selection of five different-sized Astell & Kern Provisions ear tips. The smaller of us might find the UW100 too big to be a realistic proposition, but the rest of us need to rest assured that these headphones are as comfortable as any nominal rival.

Astell & Kern Control App

(Image credit: Tom’s Guide)

Astell & Kern AK UW100 review: Controls

First things first: there’s no voice assistant compatibility here. Control is available almost entirely via the capacitive (reliably responsive) touch surface on each earbud. All the usual stuff – “play/pause”, “forward/backward”, “volume up/down”, “answer/end/reject call”, etc. – are available, and therefore the UW100 is an absolute breeze.

There’s also a control app – although ‘control’ is a bit of a misnomer. This is where you can get an indication of battery life, choose between five EQ presets, reassign touch control specifics, and toggle “ambient mode” on or off. ‘Ambient mode’ gives external sounds a boost, and there are four levels of intensity available should you decide to activate it. So while it’s a useful app as far as it can go, and stable with it, “control” – at least in terms of playback – really isn’t something it gets involved in .

Astell & Kern Control App

(Image credit: Tom’s Guide)

Astell & Kern AK UW100 review: Sound quality

No two ways about it, these Astell & Kern headphones sound great. Whether it’s the robustness of their wireless connectivity, the high-end nature of their DACs, the uncompromising engineering of their drivers, or (most likely), the combination of the three is, ultimately, only neither here nor there. It’s the result that counts — and the results here are extremely impressive.

These headphones reveal a remarkable amount of detail. Even in recordings you might think you’re familiar with, there are transient details, subtleties or virtually non-existent nuances that the UW100 will unearth and inform you about. They’re incredibly informative, but aren’t in any way analytical or intelligent about it – they simply extract every bit of information from a digital audio file and let you have it, in its entirety and in context.

Low frequencies are deep and incredibly fast as the UW100 hits solid and hard without any feeling of overhang.

Up top there is bite and shine. For the best performance, you’ll want to pair these headphones with a good quality source player and the highest quality music files to prevent high-pitched sounds from shimmering uncomfortably. But even with standard sources and materials, somehow things never cross the line of harshness. And in between, the midrange is the star of the show – the remarkable amount of detail that is revealed means the singers are fully expressed and, as a result, the vocals are full of character.

Astell & Kern 3 control app screen

(Image credit: Tom’s Guide)

The UW100 outlines a large, well-defined and fanatically curated soundstage. Even with a recording as multifaceted and complex as The Flaming Lips’ “The Spark That Bled,” there’s enough room for every element of the song to flex its wings so you can fully examine the strands of music without it. does not interfere with overall performance.

What else? Well, dynamics of all kinds – from wide “quiet/LOUD” stuff to minor harmonic variations audible in a solo piano piece – are handled with confidence. The rhythms are expressed convincingly. And there’s something elegant about the way the UW100 glides through the toughest tempos.

The flaws, as they are, have nothing to do with the sound produced by the UW100. The vaunted passive noise isolation turns out to be ‘OK-ish’, but you’ll never be safe from external noise intrusion, even if the way the headphones fit dampens it a little. And really, that’s about it.

Astell & Kern AK UW100 Charging Case

(Image credit: Tom’s Guide)

Astell & Kern AK UW100 review: Battery life

A total of six hours stored in the earphones themselves, plus three more full charges in the charging case (which, like the earphones it contains, is quite large and quite deliberately designed) gives a total of 24 hours between loads. If the worst happens, 10 minutes of AC power is enough for another hour of playback. Charging can be done wirelessly, using any Qi-certified pad, or via the USB-C socket on the charging case.

Headphones placed in the charging case

(Image credit: Tom’s Guide)

Astell & Kern AK UW100 review: Call quality and connectivity

The UW100 uses Bluetooth 5.2 for wireless connectivity, and it’s compatible with SBC, AAC, and aptX Adaptive codecs, while multipoint support lets users pair the headphones to two devices simultaneously. The mic array that deals with “ambient mode” also handles telephony – and it turns out to be more than adequate. Wind noise is suppressed fairly well and – and as long as your connection is decent, of course – the UW100 is a perfectly acceptable way to make and receive calls.

Astell & Kern AK UW100: Verdict

If you want headphones with ANC and a full set of features, look elsewhere – there are plenty of perfectly decent wireless in-ear headphones that tick all the boxes. But if you want sound that’s as full, as convincing, and as enjoyable as that kind of money can buy, and if your ears are the appropriate size, the Astell & Kern AK UW100 should definitely be at the very top of your shortlist.