ACMEE Magic Sound 4 ES9018K2M English Review


More Reality Than Magic




Construction and Design
Packaging and Accessories




  • Analytical, clean and clear sound.
  • SE and BAL 4.4mm outputs in one device, at a very good price.
  • Quality construction and design.




  • Poor price/power ratio.
  • Minimal functionality.
  • Slightly high balanced output impedance.


Purchase Link


Link to the Store




ACMEE Audio continues to grow and add new products to its catalogue. After introducing its first dongle in a limited edition, using AKM’s defunct AK4493EQ DAC, it is now back with a fully-fledged Sabre DAC. It is the ES9018K2M. With this chip a sampling rate of 192k and a depth of 24Bit can be achieved and files up to DSD128 can be played back.
The Magic Sound 4 is special because of its heritage from ACMEE’s DAPS series, adopting the same exterior surface treatment, as well as the brand’s typical grooves. Internally, it also incorporates a separate printed circuit board design for the audio circuitry, as used in the MF02s, called «Pure Ground Technology». Its purpose is to eliminate digital signal interference from the audio circuitry. Its internal design is symmetrical, while both the width and length of the wiring is the same for both channels.
It seems that the Magic Sound 4 will not be unique: after the limited edition with AK4493EQ and the current version with the Sabre ES9018K2M DAC, there may be a new version in the near future…
The design of the Magic Sound 4 is simple and pure, with LED operation, a USB Type-C input and two audio outputs: SE 3.5mm and BAL 4.4mm. We’ll see the rest of its virtues in this review.





  • Model: Magic Sound 4
  • Colour: Blue
  • Body material: 6060 aluminium
  • Sampling rate/bit depth: up to 192K/24Bit
  • Output level: SE 2Vrms/balanced 4Vrms
  • Single-ended output power: 250mW (16 ohm)/125mW (32 ohm)/26mW (150 ohm)
  • Balanced output power: 270mW (16ohm)/500mW (32 ohm)/106mW (150ohm)/53mW (300ohm)
  • SNR: SE 110dB, BAL 115dB
  • Frequency response: 15Hz-45kHz
  • DAC: ES9018K2M
  • Headphone amplifier: RT6863 x2
  • Audio power supply: ±5.5V
  • DAC power supply: Low noise LDO x3
  • USB input: TYPE-C
  • Output: 3.5mm SE , 4.4mm BAL
  • Size: 60x24x11.5mm
  • Weight: 18.58g





The presentation of the ACMEE Magic Sound 4 is simple but elegant. It comes in a small, elongated box measuring 123x63x32mm, blue in colour, with a textile-like texture. The brand name and model are printed on the top third, in holographic ink. At the base is the web address, in smaller, white letters. On the back, at the bottom, there is a sticker with some data in Chinese. After opening the box you can see the dongle embedded in a thick foam mould, underneath which is a small black cardboard box containing two cables. In short, the complete contents are:


  • The ACMEE Magic Sound 4.
  • A warranty card.
  • An instruction and specification manual, in Chinese and English.
  • A short USB Type-C to USB Type-C cable.
  • One long USB Type-A to USB Type-C cable.


The packaging is simple, straightforward, terse but pleasing. It comes with the bare minimum. Little more can be expected.



Construction and Design


The Magic Sound 4 has a clear reminiscence of the brand’s DAPs, with the same exterior treatment and the grooves that are already part of the brand’s hallmark. Its size is 60x24x11.5mm and its weight is 18.58g. It is made of 6060 aluminium and painted in a deep blue. The texts are inscribed on the sandblasted/textured surface. On the main side you can see the brand logo in the centre, underneath you can read «192K/24BIT DSD128». On the other side each connection is named. Of particular note is the «4.4BLA» caption. Just beyond the centre of this side, closer to the USB connection, there is an LED that lights green when connected. The elongated sides have 3 fins with two slots, giving that radiator look that the brand’s DAPs also incorporate. At one end are the 3.5mm SE and 4.4mm BAL audio outputs. The balanced output has a gold-plated connector, while the SE output does not. At the other end is the USB Type-C input.
Internally, the Magic Sound 4 uses the Sabre ESS ES9018K2M DAC. It also uses the RT6863 x2 amplifier chip. The audio power supply of the Magic Sound 4 amplifier adopts a ±5.5V boost and ±4.8V ultra-low noise LDO design, which effectively reduces power supply noise. The power supplies for the left and right channels of the DAC are separated, using two ultra-low noise 3.3V LDO power supplies to improve channel separation, in addition to the 3.3V power supply and the 1.2V power supply for the digital circuit. The Magic Sound 4 has 7 power supply chips in its small body.
The Magic Sound 4 stands out due to its distinctive design with its distinctive grooves on the sides, its sandblasted surface and its deep blue colour. Thanks to the 6060 aluminium, it is built like a tank and feels sturdy yet lightweight. The surface is resistant to fingerprints and looks tough against scratches. It is clear that ACMEE has not skimped on its construction, neither externally nor internally. Along with the design, they have done a good job.





The ACMEE Magic Sound 4 can be connected to a Windows 10 PC. It requires no drivers and can play 192K/24Bit PCM and DSD128 files.
It can be used in connection with a smartphone (Android or Apple) and compatible DAPS or transports. For Apple, a suitable connection cable will be required, which must be purchased separately.





Operation is extremely simple. It has a USB Type-C connection and under Windows 10 no drivers are required.
It has no volume control and has two audio outputs SE 3.5mm and BAL 4.4mm.
It has an operation LED that lights green when connected, but does not change colour to indicate the saple ratio. It also has no battery, no external buttons, so operation is extremely simple and straightforward.
With use, a very slight warming can be detected, but nothing annoying. Little or nothing else to comment on.





Looking at the power specs, I already thought they were too much. But seeing that its power is really low, I honestly didn’t expect it. With no load on the SE output, it barely gives more than 0.5V, which is ridiculous compared to what is specified. The balanced output is just double that, as usual. 1V is normal for many small DAPs and most dongles I’ve tested, but for SE. Although, there is still an aggravating factor, the output impedance. The good part is that Acmee has improved in this regard and it is not as high. As measured, the output impedance for SE is slightly over 2Ω, while for the balanced output it is slightly over 4Ω. As I say, this is an improvement for ACMEE, but they are still values that can be improved.
The only good thing to come out of the measurements is that the observed curves are quite clean and have no visible distortion even at full power. It was only a matter of time before this was not the case.



No load SE


With no load, the output voltage at 1khz is 0.524V. Very poor.



15Ω SE


With a 15Ω load, the output voltage at 1kHz is 0.455V, resulting in a power of 13.8mW. The specifications give a power of 250mW at 16Ω. No further comment is necessary.



33Ω SE


With a 33Ω load, the output voltage at 1kHz is 0.48V, resulting in a power of 7.22mW. The specifications give a power of 125mW at 32Ω.



100Ω SE


With a 100Ω load, the output voltage at 1kHz is 0.519V, resulting in a power of 2.69mW.



No load BAL


With no load, the output voltage at 1khz is 1.01V.





With a 15Ω load, the output voltage at 1kHz is 0.765V, resulting in a power of 39.02mW. The specifications give a power of 270mW at 16Ω.





With a 33Ω load, the output voltage at 1kHz is 0.889V, resulting in a power of 23.95mW. The specifications give a power of 500mW at 32Ω.



100Ω BAL


With a 100Ω load, the output voltage at 1kHz is 0.982V, resulting in a power of 9.64mW.



Frequency Response


Frequency response is flat from 10Hz to 40kHz and crosstalk is negligible. Nothing remarkable in this respect.



Output Impedance SE at 33Ω 1kHz



Output Impedance BAL at 33Ω 1kHz





The other strong point of the Magic Sound 4 is the sound, along with its level of construction. The ACMEE dongle features the typical Sabre sound, which is characterised by a neutral, bright/analytical profile. The sound is clean and transparent, fast and subtly punchy, something that provides that sparkle that gives it a more critical level of sound.
The frequency response is entirely flat, but its slightly higher-than-unity output impedance can subtly colour the frequency response of some hybrid, low-impedance IEMS. This is always a box of surprises, as the result is hardly predictable. With dynamic headphones there will never be a problem and the response will always be that of the connected headphones.
The bass reproduced is expressive, with a good level of roughness and the classic Sabre explicit high-resolution cut. I must comment that I have always been a fan of this kind of sound and that is something that is clear throughout my reviews. The low end comes across as very well defined, clear, dry, crisp, with good speed of execution, quick decay and almost no decay. The Magic Sound 4 provides the bass with good layering and layering capabilities, thanks to its high resolution and speed. This, coupled with the remarkable transparency, allows for a fairly dark and separated background to be appreciated between notes.
Admittedly, it’s not an ultra-cheap dongle, but it does have SE and balanced 4.4mm output. Normally, dongles in this price range have only SE output, some have only 4.4mm output. But the Magic Sound 4 has both. I’ve talked about power before, and it’s not the only reason I recommend using the balanced output. I feel that the balanced output has more body and sounds smoother, which is noticeable because the sound is less twangy, as well as a better stage feel and more muscle in general. Of course, these impressions are linked to a better power response, but also to a more refined, yet more melodious sound.
The mids are accurately reproduced, sparkling, pristine. The clean feel enhances the level of separation and definition, maximising a sense of air between notes. Resolution is remarkable. There is no softness that eliminates detail, but rather detail is expressed revealingly, even somewhat critically. It may sound dry, but those looking for a more analytical sound will be delighted with this twist on ACMEE’s other DAPS. All in all, the midrange is neutral, with a bright tendency that never offends and shows nuances with great ease.
Unsurprisingly, the high end is explicit, crisp and extended. Lovers of soft treble should pair the Magic Sound 4 with warm IEMS if they want the treble to be more musical. But for those who enjoy an unrestricted top end, this new ACMEE is in a league of its own. Notes in this range come across as fast, remarkably defined, even sharp, but without sounding piercing. There seems to be a command to unleash the Sabre sound, something that is accentuated in this range. This is how Magic Sound 4 achieves a pure treble sound, emphasising its definition, but without increasing its presence. It’s a question of sound profile.
With all that has been said so far, it is clear that separation is another strong point of this dongle. The location of the elements is quite precise, as the level of resolution makes it possible to discern the elements in an obvious way. There is more of a sense of cleanliness and transparency than of depth. But the good level of layering means that the sound does not appear flat. Admittedly, though, the presentation is wider and louder than it is deep. Despite the sharpness, the surrounding or three-dimensional sensation is not very high and the sound feels close rather than vaporous.





By now, what brand in the industry doesn’t have a dongle. And until AKM is re-composed, ESS Sabre is still the most widely used DAC. ACMEE has opted to use an ES9018K2M and its sound has shifted away from the warmth or neutrality of its previous DAPS. Its Magic Sound 4 dongle has a Sabre sound that is unrestricted, analytical, transparent, full of dynamics, with a remarkable sense of separation, resolute, effective and with a clear bright neutrality. The aesthetics are unmistakably reminiscent of the brand’s other models, as is the level of construction. Sound, design and workmanship are undoubtedly the strong points of this dongle. On the other hand, the functionality is very basic and the power level demonstrated is far below the specified level. It is strange that ACMEE is weak in this area, because their DAPS are powerful. On the other hand, a trend leading to success is that the output impedance is down to an acceptable level, although there is still room for improvement in this area. But it is certainly another point that fans will appreciate.



Earphones and Sources Used During Analysis


  • HiBy R3 Pro
  • Xiaomi Redmi Note 8 Pro
  • Ikko OPAL OH2
  • TFZ Tequila Pro
  • BQEYZ Autumn
  • Dunu Titan S
  • Dunu Falcon Pro
  • NiceHCK TopGuy
  • NiceHCK Lofty
  • NF Audio NM2
  • Hidizs MM2
  • Rose Martini
  • NiceHCK EBX21
  • OurArt QJ21