The AK ACRO BE100 is the first powered speaker made by Astell&Kern known for their digital audio players. This Bluetooth speaker delivers Hi-Fi sound quality through a 32-bit Hi-Fi digital-to-analog converter (DAC), a custom made woofer and tweeter, as well as a compact Class D amplifier that controls each frequency range independently. It retails at S$569 in Singapore exclusively at AV One (https://av1group.com.sg).

Astell&Kern ACRO BE100 key features:
- Unique light and shadow effect design
- Dedicated 32-bit hi-fi grade DAC
- Support for 24-bit hi-res codecs aptX HD and LDAC
- Superior stereo sound from a custom 4″ Kevlar woofer and 1.5″ silk dome tweeters
- Class-D amplifier with 55W of total power
- Ability to adjust treble and bass sound settings (0 to 5)
Design and Operations
The ACRO BE100 is meticulously designed with details, like the iconic triangular shaped speaker grille and even a triangle mould on the AC adapter. The entire surface is wrapped with faux leather to achieve a soft feel, though it would be hard to upkeep the condition over the years.
The operating buttons at on top of the speaker and touch-sensitive. The “Preset” button is used for saving FM radio station and to start Bluetooth pairing when press-hold for 5 seconds. The Bass and Treble buttons allows adjustment of the bass and treble up to 5 steps. The playback controls work only with Bluetooth-connected devices.
The rear of the speaker is where you find the necessary connectivity ports and the passive bass radiator., you can see the power. Models with FM radio will have an additional antenna port next to the AUX connector.

To power-up the speaker, push down the volume knob and hold until the knob light comes out. The playback mode will also be displayed in front of the speaker. The LED shows green in AUX (Line-In) mode, and displays blue in Bluetooth mode. To switch modes, just push down the volume knob briefly. To turn off, push and hold.

The volume control has up to 100 steps and during adjustment, the volume level will show on the front display. The volume LED turns white when adjusting.

Personally, I feel that the display indicator would look classier if the display is using high pixel density instead of digital fonts, and in a different colour.
Audio Quality
Astell&Kern has invested some R&D in the amplification and reproduction of the sound, so I’ll just list them here for info, The BE100 uses a Class-D amplifier to achieve consistent sound quality without distortion. The amp’s onboard digital crossover splits the audio signal into different frequency range to achieve clear and precisely timed sound. The 4-inch mid-bass cone is made from Kevlar fabric to improve response speed and timing. The two silk dome tweeters produce crystal clear high-frequencies, while sound-absorbing material inside the wooden cabinet seals the interior to reduce resonance.
In addition, dynamic range control (DRC) is used to protect the speaker unit as it hits maximum output power. To minimise jitter – the undesired deviation in time from the transmitted signal – the Bluetooth chipset is equipped with a 50ps clock to enable incredibly accurate sound. Support for 24-bit aptX HD (48khz) and LDAC (96khz) codecs offer the best possible wireless sound quality.

As I always mention, with all the technology, it only matters how the actual sound is reproduced. The room plays an important part to bring out the speaker sound quality and balance, so it is often not easy to match my experience with readers’ expectations. But there are certain frequency response characteristic that I can highlight which I feel is evident of the review unit. I shall start to describe the sound over Bluetooth wireless streaming.
When I tested the BE100 in a living room or bed room and seated at about 2-3 metres away, I have to turn up the volume level to above 80 to get enough loudness. I find the speaker presents an elevated upper midrange/ lower treble, making vocals sound warm and rounded. The mid and upper treble (percussion and sibilance) is bright enough to make the speaker sound sweet and clear, but not too thin or bright.
The lower bass does not resonate the room enough, the mid-bass is clean to hear the notes travel out, the upper-bass offers strong snappiness on the kicks and hits. Overall, the bass delivers uneven resonance depending on how the room responds to the resonance. I would say the speaker performs less consistently on genres with strong bass lines, like EDM and Rock, but plays nice on acoustic genres like Classical, Jazz, Instrumental Pop.
Next, I tried listening at close proximity, placing the speaker on my study table and sitting 50cm away. Even at this distance, I had to turn up the volume level to above 50. In this setting, the bass is more confident and delivers consistent resonance for all genres. The treble comparatively sounds less forthcoming, and I need to turn up the Treble level to brighten the tonality and balance the bass output. The midrange is not as forward sounding but since I am sitting rather close to the speakers, can I still hear them embedded inside the speaker plane. Thanks to the stereo speaker setup, I can hear some instrumental imaging at such close range listening.
When switching over from Bluetooth to AUX-In, the frequency shifts upwards, the bass becomes less intense, while the treble is brighter. This difference could be attributed to the source, but based on experience, generally the sound is more compressed over Bluetooth compared to direct cable.

Verdict
I enjoy the BE100 better at close proximity, as it projects all the musical details for my listening attention without getting diffused. At 55W output, the sound easily projects and fills the house with a warm and clear sound signature. The Treble and Bass fine-tuning is helpful to adjust for optimal listening balance according to the listening distance. While I appreciate the inner tech that goes into the BE100, it does not translate into what I hear due to the limitations of a single speaker unit. Nevertheless, it is a good start to Astell&Kern new product line and they could improve on the technology in other speaker form factors.




