Astell&Kern AK UW100 Review: AK4332ECB decoding chip + Knowles armature unit


Astell&Kern AK UW100

Although the AK UW100 is not a perfect true wireless earphone, it has finally achieved a breakthrough in the sound quality of true wireless earphones through its built-in independent decoding chip and efforts in tuning. In terms of passive noise cancelling effect, the leap compared to traditional in-ear TWS is also impressive enough. For now, the main potential users of AK UW100 are mainly audiophiles and digital enthusiasts who pay attention to the sound quality performance and the comprehensive listening sense of headphones. Unfortunately, the AK UW100 does not support the ANC function.

AK UW100 is Astell&Kern’s first TWS true wireless earphone with independent DAC architecture. The AKM AK4332ECB 32bit decoding chip and the high-quality Knowles full-range armature unit are configured in the left/right channel earbud respectively. For the first time, the fully balanced architecture that only top portable Hi-Fi players have on TWS products is realized: Dual DAC + Balanced Output, so that AK UW100 can deliver real, original and natural sound.

Accessories & Specifications

The accessories of the AK UW100 are similar to those of other TWS earbuds, except that there are 2 more pairs of eartips. Items in the package include: charging case, earbuds, Type-C cable, 5 pairs of eartips, and instructions.

AK UW100 specs and features:
  • Bluetooth 5.2 with AptX Adaptive
  • 6 hours playback of earbuds
  • Charging case can charge earbuds fully 4 times
  • Knowles full-range armature unit
  • AKM AK4332ECB 32bit decoder chip
  • Dual DAC + Balanced Output
  • $400 – Check latest price on: AliExpress

Appearance Design

Astell&Kern AK UW100

The size of the earbuds is acceptable to me, but the AK UW100 has a very large charging case. From a portability standpoint, it doesn’t fit comfortably into a trouser pocket, as is a jacket pocket or commuter bag where it’s intended.

Astell&Kern AK UW100

But I still really like the design of the earbuds. It is a very special, angular design that is different from other brands. If you are tired of the same TWS design, it is a very good choice.

Sound Quality of AK UW100

Astell&Kern AK UW100

Let me start with my conclusion on the sound of the AK UW100: The AK UW100 is by far the best TWS earbuds I’ve heard, especially its tuning. I’ve given the B&O E8 3rd and the Sony WF-1000XM4 sound good reviews before, but both are slightly inferior to the AK UW100.

Of course, in terms of hard quality, Astell&Kern AK UW100 is not the strongest in true wireless. But the sound of the AK UW100 is not simply winning by quality. The power of its sound quality is that, under the hardware limitations of a limited pair of armature units, it brings out a high-level, loose and full sound.

You can feel the difference within three seconds of the music starting to play. The broad sound field and the majestic dynamics instantly conquered my auditory senses. I suspected at one point that they did something like “spatial audio” enhancements, but there’s no evidence yet.

The low frequency part of the AK UW100 extends deep down, but converges quickly. The vocals are sweet, and the drums are particularly nice. The treble part has been enhanced, which is very pleasing to the hearing.

The high frequency part may be considered to be deviated by friends who prefer to observe the curve. But to me it sounds like an effective polish for bluetooth audio. You will even have the illusion that “this headphone has a high resolution”.

Noise Cancelling Effect

This is a bluetooth earphone without active noise cancelling.

I’m wondering why the AK UW100 doesn’t have active noise cancelling (ANC), but relies entirely on passive sound isolation (PNI).

Astell&Kern AK UW100

The AK UW100 offers five different sizes of silicone eartips, so you can find the one that suits you best. In the actual experience, its passive noise cancelling effect is indeed better than that of the same type of headphones, and it blocks the middle and high frequency sounds very well, especially the human voice.

In my opinion, although the passive noise cancelling effect of the AK UW100 cannot compete with the mature ANC of the big brands indiscriminately, its passive noise cancelling effect surpasses all true wireless headphones without ANC. In some application scenarios, the noise cancelling effect can even surpass active noise cancelling.

Through communication with Astell&Kern staff, the PNI noise cancelling effect of AK UW100 is mainly due to the design of the in-ear catheter and the shape and material selection of the in-ear eartips. As a result, the wearing feeling of AK UW100 is very full, which can block external noise to the greatest extent. The design of this part mainly comes from the experience accumulated in the long-term cooperation between AK and JH Audio.

In terms of actual usage scenarios, the noise cancelling effect of AK UW100 is better than that of traditional ANC earbuds in relatively quiet places, such as at home, in the office, or when walking or running downstairs in the community. The reason is that passive noise cancelling belongs to “indiscriminate isolation”, rather than “selective filtering” of noise like ANC earbuds. Therefore, in a low-decibel environment, the PNI of the AK UW100 can indiscriminately shield external sounds, allowing the listener to obtain a relatively quiet music world.

Of course the shortcomings are also obvious. The current ANC earbuds are usually reserved for human voice, allowing the person wearing the earbuds to hear others speaking. And wearing the AK UW100 to listen to music at home or in the office will basically make you completely unable to hear the voice of the person being spoken to. It is recommended to use low volume + ambient mode for such scenarios.

This earbuds has an ambient mode and four levels of intensity adjustment, but it does not provide active noise cancelling capability, which is really incomprehensible.

Of course, we can explain this product choice with “Hi-Fi earbuds do not provide ANC because it tends to provide better sound quality.” But I think it’s a little bit technically unreasonable.

Astell&Kern AK UW100

In environments with higher noise levels, such as urban roads, business districts, subways, and so on. Due to the inherent disadvantage of the PNI principle for low-frequency noise cancelling, although the actual effect is also obvious, the noise cancelling effect is still not as good as that of ANC.

Comfort & Battery Life

The wearing comfort of the Astell&Kern AK UW100 is among the best in TWS. It feels full and firm to wear, and the material of eartips is skin-friendly and soft, so there will be no discomfort even if you wear it for a long time. Although the earbud cavity is slightly larger, the catheter part is relatively small, so choosing the appropriate eartips size will not cause any discomfort. The comfort level may be related to the design experience of AK T8/T9 earbuds.

On the downside, it’s similar to previous wired earphones with a “stethoscope effect”. Since the passive noise cancelling effect of the AK UW100 is very good, if you don’t listen to music and still wear earbuds and do not turn on ambient mode, it will be a little uncomfortable. Therefore, if you want to wear the AK UW100 on your ears for a long time to sense any sound from the phone at any time, it is recommended to turn on ambient mode or wear only one earbud.

The earbud has a single battery life of 6 hours, and the charging case can charge the earbuds about 4 times. I think bluetooth earbuds for a dual DAC are excellent.

Connectivity & Interaction

It must be pointed out that I had some issues with this pre-fetched not-for-sale item.

During the first pairing, I couldn’t pair two earphones at the same time, only one earphone worked properly. After I press and hold for 10 seconds in the charging case at the same time, I completed the “factory reset” before pairing correctly.

After pairing, there are no more connection problems. I thought there would be a lot of little synchronization bugs with the two separate DACs, but it didn’t show up.

I’m not sure if the final product will have issues with the initial pairing. If there is, follow my instructions and it should be resolved.

Astell&Kern AK UW100

The connection speed of the AK UW100 is only moderate in TWS, which is significantly different from Airpods and the true wireless earbuds launched by mobile phone manufacturers.

The Bluetooth 5.2 of the AK UW100 supports common encoding formats, but does not support LDAC. The Android camp supports AptX Adaptive with adaptive variable bit rate, and generally there is no sound quality bottleneck caused by the bit rate problem.

In terms of interaction, I don’t think all surface touch-based TWS earbuds interaction methods are very reliable. And Astell&Kern is always not a strong point in software development, so the smoothness of the APP is not satisfactory.

Check lowest price of Astell&Kern UW100:


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