AFUL Magic One - R&D Magic

Besides ”audio boutique”, few keywords command as much respect and prestige as “Research and Development” and its closely related cousin, the four-letter abbreviations of cutting edge IEM technologies. But in a market where everyone from mom-and-pop shops to big players claim that they do cutting edge “R&D” in their new IEMs, it’s perhaps necessary to sit back and ask ourselves: what is IEM R&D, really?

In this context, let’s talk about AFUL Magic One, a daring release carrying only one Balanced Armature (BA) driver.


  • What I look for in an IEM is immersion. I want to feel the orchestra around me, track individual instruments, and hear all of their textures and details. I’m not picky about tonality, as long as it does not get in the way of immersion.
  • I rate IEMs within with a consistent scale from 1 (poor) to 3 (Adequate) to 5 (outstanding). Ratings are assigned by A/B tests against benchmark IEMs, regardless of the retail price.
  • Ranking list and measurement database are on my IEM review blog.
  • Terms used in my reviews are consistent with the glossary by Headphonesty
  • This review is based on a review sample from Hifigo (Thank you!). I have no affiliation with or financial interest in Hifigo and AFUL.
  • The unit retails for $140 at the time this review was published. Unaffiliated link:

Testing setup: Local FLAC files -> iBasso DX300 (stock player app) -> stock cable (4.4mm) -> IEM -> SpinFit W1 (Small)


What is Magic One?

AFUL Magic One is a single BA IEM that retails for $140. Yup, just one BA driver. No fancy Beryllium or DLC membrane. No passive radiator. No hidden bone conduction driver. Just one full range BA driver custom-made by AFUL.

Well, that description mostly, but not entirely captures the internals of Magic One. The BA driver is aided by two innovations:

The first one is an complex electronic circuit that shapes the frequency response of the driver.

The second one is a resonance chamber and elongated resonator tubes (which a fellow audio geek compared to a digestive organ) that strengthen the bass response of the BA driver.

Together, these components transform the response of the BA driver from this:

(Credit: AFUL)

To this:

(Credit: AFUL)

At this point, you might be asking: why spending all of that effort to make a single BA IEM? After all, it is well known that full range BA drivers have the short straw when it comes to extensions at both ends of the frequency spectrums, which are crucial for an “audiophile” sound quality. That’s the question that I kept asking myself ever since I saw a post on social media announcing the existence of Magic One.

The official answer from AFUL is as follows:

“many high-end HiFi in-ear monitors at the premium level adopt multiple drivers with precise crossovers to achieve excellent performance in each frequency band. However, this approach comes with certain problems: 

  1. The different driver units lack accuracy in connecting and blending their sounds.
  2. They can cause vibrations and interferences with each other.
  3. Each unit can have slight variations in timbre.

These issues often lead to a degradation in sound quality. On the other hand, using a single balanced armature (BA) driver unit can overcome these problems by offering excellent performance in each frequency band without any connection or interference issues.”

Has AFUL been successful with this vision? Let’s read on.

Subjective Experience

The experience with any IEM starts with fit and comfort. In my experience, the comfort of an IEM relies on three factors: the size of the shells, the shape of the nozzles, and the pressure release mechanism. Magic One does a great job with the first two factors. Thanks to the one-driver design, the shells of Magic One are quite small so it does not stretch or create any hot spot in the concha area of my ears. The nozzles are relatively thin with a medium length, allowing me to wear the IEMs at a proper depth without putting any pressure on the ear canals.

The area where Magic One falters is the pressure release. The superb seal it provides can, over time, lead to a gradual pressure build-up in the ear canals. It reaches a point where I have to give my ears a breather and pull out the IEMs to let the pressure equalize. This hiccup is a common woe with IEMs rocking balanced armature drivers, something you might not have encountered if you’ve stuck to the dynamic driver camp.

Because an IEM does not has a sound of its own, its sound can only be described indirectly through the musics it reproduces. Therefore, in this part of the review, I’m going to paint of a picture of the sonic performance of Magic One by describing how I hear some of my favourite tracks when using Magic One.

Before we move on, let’s have a look at the tuning vision of AFUL with Magic One: “… a touch of warmth, the overall quality of the pair can be compared to that of a 4 BA driver IEM or even a dynamic driver IEM. … a powerful and elastic bass response, similar to what you would expect from a dynamic driver. However, it still maintains the high-density sound quality typically associated with a Balanced Armature (BA) driver … excellent extension in the treble range, reaching up to 18KHz before gradually tapering off. While the treble may be slightly bright, it is not harsh or fatiguing, creating accurate sound reproduction for various instruments”

The first piece I want to discuss is the first movement of the Sibelius violin concerto performed by Heifetz. “Precision” would be the keyword that I use to describe the performance of both Heifetz and the Magic One. The way Magic One presents the music reminds me of a properly focused camera lens. Every instrument has a sharp outline and pin point positioning, accurate to the spatial information embedded in the music. In this violin concerto, Magic One places me right at the conductor’s podium with the orchestra around me. The string section can appear outside, slightly behind my ears. The wood wind section seems to sit in front of me, but at a higher position than the string section at the front. The only difference from a real world orchestra is that the violin of Heifetz seems to come from the front, slightly above my head, rather than behind the conductor from the left, where a soloist usually stands.

Dynamics are conveyed with finesse. Loud segments are appropriately impactful without any uncomfortable brightness. Noteworthy is the tactile richness in lower frequencies, capturing the nuances of string plucks and contrabass notes. There is also a satisfying sense of tactility in the lower frequencies of Magic One, evidenced by the snapping sensation of string plucks by the cello section. The notes played by contrabass also has texture and a rumbling sensation.

The detail, the imaging, and the dynamic together create a sense of magnetism with this recording. I found myself losing track of time in dissecting and following every small things going on the orchestra. When the violin is the star, I focused on the nuances of the violin. When the main violin fades away, the details of the orchestra took over.

Shifting to the “A Way of Life” soundtrack from The Last Samurai, the Magic One showcases a different sonic landscape, emphasizing ambience and spatial diffusion. Different from the the previous violin concerto, this soundtrack is mixed to convey a misty, slightly hazy ambience. The Magic One successfully reproduces that the misty ambience, creating a pleasing, hazy dome of sound. Sounds unfold into the mist at a distance, avoiding an overly forward presentation.

The next sonic aspect of Magic One that I focus on is the bass. Of course, there are many ways to analyse and describe the bass response, but at the end of the day, to me, the only thing that matters is that whether an IEM can make me tap my toes and bob my head. Doing so requires the bass to be just right to convey a sense of energy and rhythm. Too much bass, and the presentation feels muddy and lack the sense of musical pulses. Too little, and there is no energy.

In order to test the bass response of Magic One, I listen to the Gundam 00 The Movie OSTs. I found that Magic One has just enough bass to convey the necessary energy and rhythm of these tracks. It achieves this through precise bass delivery rather than sheer loudness and extension of the bass. The best way to imagine the bass response of Magic One is to think about plucking a tightly stretched string. All of the bass energy of Magic One is focused tightly at the attack end of bass notes, making them stand out. And because they stand out, the beats become emphasised, and thus the music has a strong sense of rhythm. Still, the Magic One still lacks the subbass extension of its siblings carrying DD woofers, thus the amount of energy convey is still day-and-night different.

Let’s wrap up by delving into how the Magic One handles vocal music, with a focus on Pentatonix’s Volume 4.

Firstly, all vocals take the center stage, deliberately placed forward in the soundstage, aligning with the recording’s intent. This distinguishes the Magic One from some of my other preferred IEMs, which tend to artificially downplay certain frequency ranges, creating a more distant overall sound regardless of the intended positioning of a track.

The precision in the Magic One’s presentation continues to stand out. It adeptly weaves Pentatonix’s tight harmonies into a cohesive whole, capturing the resonant ringing when the notes harmonize perfectly. At the same time, it also excels at distinguishing individual voices, from Kirstin’s soaring soprano to Avi’s deep bass line. The clarity and texture of bass line by Avi and Kevin were highlights for me.

Fortunately, the precision of Magic One doesn’t translate into sharpness or unnatural timbre. All voices sound accurate, avoiding the thinness often associated with “well-tuned IEMs.” A subtle warmth permeates the tonal presentation without adding a distinct color to the midrange. For me, the tonality of the Magic One represents an improved version of “neutrality.”

Finally, the Magic One showcases robust detail retrieval. In tracks like the penultimate “Can’t Help Falling In Love,” it captures subtle nuances, like the echo effect in quiet moments between musical phrases.

Frequency Response Analysis

Frequency response of Magic One against the Harman in-ear target. Measurements were done with an IEC-711-compliant coupler and might only be compared with other measurements from this same coupler. Visit my graph database for more comparisons.

It is helpful to think of an IEM as a filter that highlights or subdues different parts of the incoming audio signal. This effect can be measured objectively by the squiggly lines above, called Frequency Response (FR) graphs, which measure how loud an IEM is at different frequencies from 20Hz (bass) to 20kHz (upper treble). Subjectivity is how your ears and brain interpret the effect of that filter on your music and decide whether it is “enjoyable.” There are some “rules of thumb” when it comes to tonality, but most interesting IEMs usually bend the rules masterfully.

The frequency response of Magic One exhibits characteristics of many new IEMs that I consider “well-tuned”, such as the 7th Acoustics Supernova.

Essentially, Magic One takes the main ideas of the Harman target, such as the need for an upper midrange boost (a.k.a., ”ear gain”), the need for treble to gradually rolls off comparing to the upper midrange to avoid harshness, and the need for a bass boost.

At the same time, it reduces the amount of upper midrange and increases the amount of lower midrange and midbass to create a richer, more pleasing, and arguably more realistic, than the Harman target.

As you can see, Magic One traces the frequency response of Supernova, an IEM whose tonality I absolutely adore, very closely.

Graph’s credit: Super* Review

Interestingly, Magic One also traces the -10dB target, which is essentially a diffuse field measurement with a -10dB tilt (more lower frequencies, less upper frequencies) using the more accurate B&K 5128 system. If all of these sounds like alien language to you, don’t worry. The gist of it is Magic One closely follows an promising new target that sounds more pleasant and arguably more “correct” than the current version of Harman in ear target.


Resolution is a fascinating subject due to the difficulty of pinning down what it really is. To me, “resolution” can be broken down into three components: (1) Sharpness, incisiveness, or “definition” of note attacks (see the figure above). (2) The separation of instruments and vocals, especially when they overlap on the soundstage. (3) The texture and details in the decay side of the notes. The first two give music clarity and make it easy to track individual elements of a mix. The last provides music details and nuances. Smooth and well extended treble response plays a crucial role.

As you have seen in the subjective impressions, the resolution of Magic One is rather good. The strength of this IEM lies in the way it presents the tack sharp boundary between instruments and and very well defined note attacks across the frequency spectrum. You might have also noticed that I didn‘t provide many positive remarks about the the micro detail retrieval of Magic One, about the nuances and textures.

So, how good is the resolution of Magic One in the grand scheme?

To answer this question, I rely a series of A/B tests against some of my trustworthy benchmarks.

For the first test, I listened to the third movement (Gavotte en Rondeau) of the Violin Partita No. 3 by Bach, performed by Leonidas Kavakos. As you know, violin solos such as the Partita No. 3 are very sparse music with only two “instruments”: the violin itself, and the reverberation of the recording hall. Therefore, these recordings are excellent for dissecting the “true resolution” of IEMs, meaning their ability to distinguish and present the minute, fine-grained details and textures in the music.

Since I have a high expectation of Magic One, I conducted the first test directly against a “heavy weight”, the venerable Andromeda 2020, my “gatekeeper” of the high-end resolution. The first challenge for me in this test was to overcome the “shock” due to the contrasting tonality of these two IEMs. But I digress, so let’s talk about resolution. Unfortunately (or fortunately, depending on your perspective), the Magic One is still a solid step behind. Whilst Magic One manages to extract all the surface details, I can hear more micro details, such as the sympathetic resonance of the violin or the subtle scratchiness of the bow against the strings, with the Andromeda 2020. Even when I turn up the volume higher than a safe level, I still had a hard time picking those details with Magic One. The refinement of the reverberation sound (a.k.a., the “air”) is also higher with the Andromeda 2020.

For the second test, I lowered my expectation and pitch the Magic One against the Moondrop Blessing 2, my benchmark of “good” resolution. Interestingly, I found the Blessing 2 to be ever-so-slightly harsher in the upper frequencies and thicker in the lower frequencies than Magic One. Ignoring the tonal difference, I found that Magic One presents details with better clarity and definition. For example, when Kavakos plays chords, the notes sound cleaner on Magic One. Still, I don’t find the difference between these two IEMs to be practically significant. Thus, I would rate Magic One’s resolution as “good.”

Soundstage Imaging

Stereo imaging or “soundstage” is a psychoacoustic illusion that different recording elements appear at various locations inside and around your head. Your brain creates based on the cues in the recording, which are enhanced or diminushed by your IEMs, your DAC, and your amplifier. Some IEMs present a wide but flat soundstage. Some present a “3D” soundstage with layering, depth, and height. In rare cases, with some specific songs, some IEMs can trick you into thinking that the sound comes from the environment (a.k.a., “holographic”)

As I alluded to in the subjective experience, Magic One has an excellent soundstage imaging capability. It can sit an orchestra with pin point precision in a 3D space. At the same time, it can convey a hazy, misty ambience as a dome of sound around the head should the music is mixed that way.

The key question at this point would be “how good?” Again, we rely on a series of A/B tests.

For the first test, I compare the Sibelius violin concerto between Magic One and the venerable Moondrop Blessing 2. To me, it was not a difficult comparison as the difference was clear from the first music phrase. Magic One puts the violin solo and the string section of the orchestra on two different planes, one closer, one further. The Blessing 2, on the other hand, was never able to create that depth illusion as it puts everything on the same flat plane. On the plus side, Blessing 2 has a wide and more open perception of soundstage, likely thanks to the air vents on the faceplates. Still, I would put Magic One ahead of Blessing 2 in soundstage imaging. It provides a more immersive experience.

The next test was between Magic One and the venerable Campfire Audio Andromeda 2020 was much more difficult for me. Magic One trades blow with Andromeda in terms of the 3D illusion of the soundstage and the positioning of instruments within that stage. That said, these IEMs present the stereo image of the Sibelius violin concerto in very different ways. The soundstage of Magic One is more “logical” and realistic, placing me at the conductor’s podium with the orchestra sitting in an 180 degree arch around me. The soundstage of the Andromeda, on the other hand, is all over the place. The cellos and contrabass seem to come from behind my ears rather than right next to them. Some instruments are right in the middle of my head, some floating slightly front left or front right. It’s entertaining and unique for sure, but not realistic. At the end of the day, I would put both Magic One and Andromeda at the same level, and favour one or another depending on my mood.


Compare against Performer5 and Performer8

Vs P5 (NiceHck Black Cat cable, FiiO HS18 medium ear tips)

  • The midrange of P5 is denser and pushed forward toward my head more. This is likely the result of the hump at 1.5kHz. This presentation reminds me of the Elysian Acoustic DIVA 2023. It is not my favourite sonic presentation.
  • When I listen to the Sibelius violin concerto recording by Heifetz, I found P5 do not provide the sharp boundary and precise instrument placement that I heard from Magic One. I would also say the inner details of each instruments are slightly better with Magic One, though the gap is practically negligible.
  • Where P5 excels is the bass response. Whilst the bass of P5 does not have the same clean attack as the Magic One, it has better body and physical impact, likely due to better subbass extension. As a result, when I listen to “Final Mission - Quantum Burst” in the Gundam 00 Movie OST, the sense of energy that P5 conveys is simply higher.
  • P5 is also more comfortable due to having proper pressure release mechanism.

Vs P8 (Stock cable, SpinFit CP100 Medium ear tips)

  • Magic One is significantly more difficult to drive than P8
  • The tonality and soundstage presentation of two IEMs are quite different, mostly due to their divergence in the 1kHz to 4kHz region. For example, when I listen to the Sibelius violin concerto by Heifetz, I found both the violin and the orchestra are pushed forward more, with less gaps between instruments. I personally find the violin to be unnaturally forward, yet the briliance “shine” in the upper midrange of the violin is not there with the P8, whilst it is there with the Magic One.
  • Both IEMs have similarly precise instrument placements. However, due to the midrange quirks above, I find the soundstage of Magic One more spacious and ultimately more interesting.
  • P8 is one step ahead of Magic One in terms of the inner details of each instruments. Simply put, I hear a bit more details, and those details are more sharply defined with P8. However, the gap is not large and might not be practically significant for some listeners.
  • The bass of P8 is like a combination of Magic One and P5. It has the tactility and precision of Magic One but with proper subbass extension of P5. It might not be as indulgent as the bass of P5, but more energetic than Magic One.

Rating and Conclusion

Let’s go back to the original question at the top of this review: “what is IEM R&D?”

To me, R&D means surpassing the state-of-the-art in a way that benefits the end users. Being the first one to use an exotic driver technology or the first one to jam an insane number of drivers into an IEM means little unless those innovations lead to a new height in sonic quality or make the existing high-end sounds more accessible. In the case of Magic One, the innovations of AFUL push the single BA configuration to the new height, matching or exceeding the previous multi-BA releases one some key aspects. By pursuing the single BA configuration, AFUL also managed to create a smaller, more comfortable, and likely more cost-effective IEM.

So, yeah. To me, Magic One is one of the more impressive R&D outcomes in our little hobby. High recommendation and seal of approval.

What I like about this IEM:

  • Precise and 3D stereo imaging
  • Excellent instrument definition and separation
  • Excellent tonal balance and timbre
  • Small and comfortable shells
  • Tactile and snappy base response
  • Quite difficult to drive (so I can use my powerful DAP and DAC/amp)

What could be improved:

  • The subbass extension is predictably not good
  • Pressure build up
  • Quite difficult to drive (so my go-to portable gears do not drive these to full potential)

Absolute Sonic Quality Rating: 4/5 - Great (Tonality 5 - Bass 3 - Resolution 3 - Staging - 4)

Bias Score: 5/5 - I love this IEM.