Astell & Kern UW100 review: Clear sound for most ears

Astell & Kern probably wasn't thinking of the average listener when it made the UW100 earbuds. These are the company's first foray into cutting all cords and going true wireless, yet the focus on sound above all else stands, and the hope is that it will serenade ears better than your average pair would.

The reputation is certainly there to pull it off. The Korean brand has built itself up as a reliable option for audiophiles who will accept no less than the best sound for their money. The UW100 are a first, though, so their ability to start out strong here has plenty to do with how good they sound no matter what you play.

Astell & Kern UW100: Price and availability

Astell & Kern launched the UW100 in March 2022, and you can find them at their original price of $300. High-end audio stores may carry these because of Astell & Kern's audiophile reputation, though it's unclear if they will drop in price in the short term. Availability from the company's own site has been limited and is expected to free up this summer. You can also shop them at B&H Photo.

Astell & Kern UW100: What's good

When I come across a pair of earbuds that just sound really good out of the box, I take notice. That is how I felt about the A&K UW100, which are tastefully engineered to deliver a clear and balanced soundstage that I think would be easy for anyone to appreciate. 

The key lies in the mids, which are often the first casualty or afterthought with wireless earbuds. A&K did it by prioritizing the very things the average listener will likely not care about. For example, the UW100 have a 32-bit DAC (digital-to-analog converter) and balanced drivers from Knowles, another reputable brand for high-end audio. Without getting too technical, what this means is the UW100 don't use dynamic drivers focused on different frequencies, but rather on armature drivers that deliver better balance, overall.

There's a fair bit going on under the hood, and you don't need to know all about it. The main point is that everything just works, and that includes the supported Bluetooth codecs, like aptX Adaptive, which gives supported devices, like most of the best Android phones, the ability to play tunes at better 24-bit hi-res quality. You do need a source to play at that level, like Tidal does with its Hi-Fi and Master settings, for instance, but the ability is there. 

By and large, Android phones support aptX HD, which should, in theory, play in 24-bit, but doesn't always seem to do so. Again, it matters if the phone and app you're using supports that. Spotify doesn't yet, whereas Tidal does. Otherwise, the earbuds defer to the standard 16-bit resolution aptX plays. 

A&K says that will all get straightened out with upcoming firmware updates, and here's to hoping that happens because the foundation is already great. I was expecting the A&K TWS app to offer a full equalizer to really take things to another level but was only met with a select few presets. They're pretty good, and even include a gaming mode, but I would want a pair of audiophile earbuds to give me the tools to tailor the sound as precisely as I want. 

The good news is that you will probably like how good the UW100 sound with different musical genres anyway. Don't fret if you like hip-hop or anything with bass because the Bass Emphasis preset gives plenty of love to the lows. If you prefer rock, jazz, house, pop, or whatever else, there's a good chance those songs will sound great as well. I just wish more options were available within the app's EQ.

I haven't mentioned the fit yet, but that does play a role. A&K includes five different sets of ear tips in the box. The earbuds themselves are bigger than your average pair, and that could pose a problem for smaller ears. Despite that, they can get pretty comfortable when you find the right fit, and the passive isolation is excellent — all the more important since there is no active noise cancelation (ANC) here.

The ambient mode has four levels to adjust when it's on, giving you a fair bit of leeway into how much background noise you actually let in. With one being the lowest and four the highest, there's some excellent clarity here. 

Even call quality holds up well. You don't have the advantage of ANC to block out noises to make calls more audible in louder settings, but otherwise, I found the UW100 perfectly fine for chatting on the phone.

The touch controls are easy enough to figure out and retain, which is always nice, and with such a large area to tap on, it's rarer to make mistakes. Options are fairly limited, but you can allocate a couple of different controls to either side.

Battery life is adequate at up to six hours per charge, though volume levels will determine if you can make it that far. I usually cracked five hours in my testing. The case has three extra charges for a full total of 24 hours, and in a pinch, you can plug in for 10 minutes to get up to an hour's playback. A&K included support for wireless charging as well, for when you don't want to plug in via USB-C.

Astell & Kern UW100: What's not good

Not having ANC in earbuds at this price is a stinging omission. Granted, audio quality is the primary focus, but A&K's claims that passive isolation can deliver similar results are simply not true. A snug fit? Sure, that's more than possible, only there's no way you can block out the same level of ambient noise.

The fit is also suspect when it comes to talking or chewing gum, as I found out when I did both at the same time. The UW100 wiggled loose several times when I was talking and I had to be careful putting them back in because on two occasions, I accidentally ended the call when adjusting the right earbud. 

Then there's the case, which is not as pocket-friendly as other earbuds often are. It's understandable to have a bulky frame for earbuds that have a little heft to them, and they're not the biggest case I've come across, but the overall size is noticeable. So is the lack of an IP rating for water or sweat resistance. If you're thinking of using these during workouts or runs, beware that it's not a guarantee they can handle them.

As mentioned earlier, the app really could offer more customization than it currently does. Maybe A&K thinks most people who would wear these wouldn't want that, but I have a hard time seeing it that way. The sound, as superb as it is, could hit new levels — and appeal to every type of user at the same time. As is, the EQ and touch control features feel too restrictive.

The whole DAC and hi-res situation also needs to come into better focus. It's great that they support aptX Adaptive (and AAC), but don't assume right away that you are getting the hi-res treatment right out of the box. Future firmware updates will tell us more about how much smoother all this goes. If you're not listening through Tidal or listening to hi-res music files, it may not matter, but part of the allure here is to introduce people to what better quality sounds like.

Astell & Kern UW100: Competition

The Astell & Kern UW100 are tough competitors when it comes to what they do best, which is to play great sound. Look at the best wireless earbuds out there, and you will find a good mix to choose from, though a few options do stand out. The Sony WF-1000XM4 are easily among the best available and do offer ANC, perhaps even the best ANC, as our reviewer noted. Yet, the UW100 do manage to hold up very well against them from a sonic point of view.

The Sennheiser Momentum True Wireless 3 are among the best you can find for sound, with IPX4 splash resistance, ANC, and wireless charging. If you are looking for something with hi-res support, the Technics EAH-AZ60 can handle LDAC streaming, as do the popular Bowers & Wilkins PI7 if you're willing to pay more for another high-end audio brand. 

Astell & Kern UW100: Should you buy it?

You should buy this if...

• You care about sound quality
• You want hi-res support
• You want a good ambient mode
• You don't have small ears

You shouldn't buy this if...

• You want active noise cancelation
• You want something smaller
• You need more app customization
• You prefer to spend less
• You intend to use these during workouts/runs

The focus and purpose here are as clear as the sound coming out of the Astell & Kern UW100. Audio fidelity trumps all other features, and with good reason, because these earbuds deliver no matter what content you choose to listen to. 

You don't have to be an audiophile to appreciate what you get here because the results aren't as subjective as you might think. You just have to jump in knowing that you don't get some of the staples of other earbuds.

However, these earbuds don't offer ANC or any type of water resistance rating, so if you were hoping to completely block out sound or use these to work out, you should probably look elsewhere.

Even so, these earbuds pack a punch when it comes to smooth silky audio and are also able to handle phone calls pretty well.