Unique Melody MEST Mk3 - Soundstage Magic

The Unique Melody MEST family of IEMs has always intrigued me due to its unique combination of various driver types, particularly the enigmatic Bone Conduction Drivers (BCD), and the reputation for a “holographic” soundstage. However, the high price point and limited availability in Australian hifi stores have prevented me from experiencing them firsthand. Instead, I’ve had to rely on reading about them and hearing others praise their performance. Fortunately, my curiosity is finally satisfied as I get the chance to spend quality time with the legendary MEST, thanks to the Australian Head-Fi Tour. Now, it’s time to subject these IEMs to a thorough evaluation and see if they live up to the hype. So, let’s dive in.

Forewords

• 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.
• This review is possible thanks to the Australian Head-Fi Tour (Thank you @Damz87 for arranging) I have no affiliation with or financial interest in Unique Melody. The unit retails for A$3200 (blue version) or A$3900 (red version) at the time this review was published.

Sources for listening tests:

• iBasso DX300 (for all A/B tests)
• FiiO K7
• L&P W4

Local FLAC files ripped from CDs or bought from Qobuz were used for most casual listening and A/B tests. My playlist for A/B tests can be found on Apple Music here.

All of my listening was done with XXXX ear tips. I listen at a medium volume. I usually turn up the volume until the midrange is fully audible and detailed, unless a treble peak or overwhelming bass prevents me from doing so.

Specs

• Driver: 1 Dynamic Bass Driver + 2 BA Mid Drivers + 2 BA treble Drivers + 4 EST Ultra - High Drivers +1 UM patented Silver-Palladium Alloy Piezoelectric Bone Conduction Driver
• Connector Type: 2-pin 0.78
• Impedance: 14 Ohms
• Sensitivity: Unknown

Build and Comfort

Accessories: The unboxing experience and packaging of MEST III left me with mixed feelings. Considering the A$3900 price tag, I had expected something more premium and refined. However, the overall presentation feels somewhat underwhelming. Fortunately, while the accessory selection is not as extensive as some mid-fi IEMs, the items provided are practical and interesting. Included in the accessories kit is a leather puck case in a dark teal color. The case’s height appears slightly taller than usual, possibly to accommodate the gigantic cable. Additionally, there is a cable clamp, crafted from the same leather material, which serves its purpose well in keeping the cable organized.

Unique Melody also offers two types of in-house designed ear tips, which play a significant role in shaping the sound signature. I found these ear tips to have a considerable impact on the audio experience, and we will delve into their influence further in the pairing section of this review.

Lastly, the package includes a cable created by the renowned cable maker, PWA. And I have a lot of bones to pick with this cable.

Stock cable: I’ll pull no punches: the cable is the weakest link in the accessory pack of MEST III. The cable has two parts. The parts from the splitter to the ear pieces are simple and soft. I have no complaint. The part before the splitter is problematic. It is simply too stiff to the point of impeding the usability of the IEM and making me worry about the longevity of the 4.4mm socket of my music player. The best way to describe this part of the cable is to think about the extension cord of a power board. It is unyielding and forces the 4.4mm connector to rotate in the socket rather than coiling around to conform to how you sit with the cable.

Stock cable: I’ll pull no punches: the cable is the weakest link in the accessory pack of MEST III. It is composed of two parts. The section extending from the splitter to the earpieces is simple and supple, and I have no complaints about it. However, the segment preceding the splitter is very problematic. The best way to describe this part of the cable is to think of an extension cord used in power boards. It’s excessively stiff, to the point where it hinders the overall usability of the IEM. Moreover, this stiffness raises concerns about the longevity of the 4.4mm socket on my music player, as it forces the 4.4mm connector to rotate within the socket rather than conforming to the natural positioning as I wear the IEMs.

Earpieces: The earpieces of the MEST III are constructed with carbon fiber shells. They look great in photos. However, upon closer examination, I noticed a few minor areas for improvement in terms of build quality. Specifically, the polishing of the shells could be refined, and the finishing around the air vent for the dynamic drivers might benefit from some attention. On the positive side, the earpieces are light and surprisingly compact despite accommodating multiple driver units, making them comfortable to wear for extended periods.

Comfort and isolation: In terms of comfort, I found the MEST III to be quite pleasant to wear. The IEM’s lightweight construction and smaller shells contribute to a comfortable fit, allowing them to sit flush against the concha of my ears without causing any discomfort or irritation. This comfortable fit is particularly beneficial, as it maximizes the contact between the earpieces and my ears, enhancing the experience with the Bone Conduction Drivers (BCD) technology.

On the note of isolation, the MEST III performs surprisingly well, providing a level of isolation similar to that of sealed IEMs. However, I did encounter one drawback in the form of driver flex on the right earpiece. This phenomenon, characterized by a crinkling sound when adjusting the earpiece, is attributed to the flexing of the dynamic driver. While not a significant issue, it’s worth noting for those who may be sensitive to such occurrences.

Tonality

Frequency response of MEST III. The measurement might NOT capture the effect of MEST’s BCD. 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.

Sound signature: In my previous encounter with the MEST series, specifically the MkII model, I discovered a lean and somewhat analytical sound signature. Thus, I was taken aback by the shift in tonality with the MEST III, which exhibits a neutral-warm character. The MEST III presents music with a warm hue and additional body comparing to Harman-tuned IEMs or U-shaped IEM, but the colouring is not to the extent of Andromeda 2020 or VE Phonix.

Midrange: During my listening session with “Jolene (feat. Dolly Parton)” by Pentatonix, I observed that all the voices sounded natural with good warmth and body, without an overly colored presentation. The balance between male and female vocals was quite even, with no particular voice overpowering the mix. Notably, the bass voice, which often gets buried in IEMs with leaner and brighter tonalities, remained discernible and well-articulated.

Next, I focused on “Bach’s Violin Sonata No.1 in G Minor: Presto” performed by Kavakos. This track exemplifies everything commendable about the MEST III’s sound, including its warm-ish tonality, attention to detail, and holographic soundstage. The violin’s warm hue with added body still maintained its brilliance without sounding thin or harsh. The midrange offered a wealth of details and nuances, capturing subtle movements and even the violinist’s breath during quieter sections, adding a sense of realism to the recording.

Proceeding to “Game of Thrones Medley” by 2CELLOS, my go-to test track for evaluating timbre, tonal balance, and congestion, I noticed that the cellos had a warm and rich tonality. However, I detected a slight tendency towards being overly full and sometimes bloomy, indicating the colored nature of the MEST III’s tonality. Despite this, the IEM managed to avoid muddiness or congestion even when the music became dense around 1:30. The layering and separation remained remarkably accurate, with the two cellos distinctly separated and precisely positioned on the soundstage. This clarity made it easy to pinpoint their locations during the performance.

Treble: Despite the rather intimidating treble peak shown in the graph, I was pleasantly surprised to discover that the MEST III offers a smooth and easy-going treble region. When listening to “Livin’ On a Prayer” by Bon Jovi, a track I use to evaluate tonal balance, sibilance, harshness, and transient behavior, I noticed an absence of shoutiness or harshness in both vocals and instruments. Interestingly, the cymbals and hi-hats were slightly less pronounced than expected. However, the MEST III managed to retain the energy and sense of rhythm in the music, keeping it engaging and compelling.

This observation remained consistent when listening to “Beat It” by Michael Jackson and “G.O.A.T.” by Polyphia. The treble remained free from harshness or piercing qualities, while still delivering sufficient energy and presence. The treble’s quality is of high standard, evident in the nuanced textures of cymbals and hi-hats across all the test tracks mentioned.

If I were to nitpick, I would mention a slight imbalance in the amount of treble, particularly around the 8kHz to 10kHz range, compared to the rest of the frequency response. This became noticeable when listening to the claps at the beginning of “Synchro (Bom-ba-ye)” by Tokyo Kosei Wind Orchestra, a track I use to assess treble tonal balance. The claps exhibited a somewhat steely timbre, hinting at the slight imbalance. On the positive side, the claps demonstrated excellent crispness and detail, with a strong sense of reverb and decay around the notes.

Bass and dynamic: As mentioned earlier, the MEST III impressively conveys a strong sense of beat and rhythm, contributing to an energetic musical experience. Listening to “Beat It” by Michael Jackson, I noticed the impactful and powerful attack of each kick, enhancing the song’s energy and drive.

Moving on to “Let the Battles Begin!” by Square Enix Music & Nobuo Uematsu, I found the dynamic swings or “slams” of the orchestra on the downbeats to be forceful and energetic. Notably, these dynamic transitions were devoid of the rounded transient behavior I encountered in another recent top-of-the-line IEM.

Additionally, “Battle Bar” by Yuki Hayashi, a test track I use to closely examine an IEM’s bass response, showcased the MEST III’s clean leading edge and excellent decay and texture in the bass notes. This quality translates into the drums’ decay having a distinct and tangible “brrrrm” sensation rather than a textureless and indistinct “ummmm” hum.

Despite the seemingly glowing description of the bass and dynamic performance of the MEST III, I must admit that I am not entirely satisfied with this aspect of its sound. In comparison to some other top-of-the-line IEMs like the U12T, Phonix, and certain single dynamic driver IEMs with robust dynamic capabilities, the MEST III does not scale the dynamic swings as strongly and decisively. While the MEST III does offer dynamic swings, they lack the visceral impact and strong contrast between the moments of silence, almost creating a negative pressure, before the bass drop and the powerful WHAM! slams of the bass or orchestra. This presentation sometimes leaves me feeling a bit wanting, as if I am waiting for more impact and intensity from the MEST III’s dynamic performance.

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”)

One of the brightest aspects of the MEST III is its soundstage imaging, which happens to be the most compelling reason why I wanted to add it to my collection.

Before diving into the details, it’s essential to dispel any misconceptions surrounding the “holographic” soundstage claims. While descriptions may lead to expectations of an IEM that places the main vocals and instruments at phantom speakers in the room, outside of one’s head, similar to what a two-channel speaker system can achieve, this isn’t the case with the MEST III, nor with other IEMs like the U12T or Andromeda 2020.

Nonetheless, the MEST III’s soundstage is far from ordinary in the context of IEMs. Listening to “Jolene (feat. Dolly Parton)” by Pentatonix, the experience is akin to sitting in a dimly lit room with closed doors and curtains, with the voices floating around the head. Dolly Parton’s voice is presented with presence, rich in details and texture, yet it doesn’t feel intrusive or in-your-face. The center of the stage doesn’t forcefully reside inside the head, nor does it overly push forward like Airpods with crossfeed activated. Instead, the soundstage naturally hovers slightly at the front part of the head, sometimes seemingly in front of the face.

Unlike many IEMs that present the soundstage with distinct left, center, and right blobs, the MEST III crafts a dome-like environment where instruments and vocals can be freely positioned in all directions—left-to-right, near-to-far, and low-to-high. This soundstage characteristic is particularly enjoyable when listening to “Synchro (Bom-ba-ye)” by Tokyo Kosei Wind Orchestra, where the snare (or hat) seems to float above my head, while the orchestra spreads around my head with a sense of distance.

Where the MEST III truly excels is in its ability to shape a dome or arc of reverb around my head, creating an incredible sense of space that almost feels as if I’m seated in the recording hall itself. This effect is strikingly evident when I listen to “Bach’s Violin Sonata No.1 in G Minor: Presto” by Kavakos. The sense of space achieved with the MEST III becomes even more apparent in its absence, when I switch back to my U12T and Andromeda 2020, both of which are already strong soundstage performers. There’s something extra and captivating about the way the MEST III crafts the sense of space in this recording, making it quite addictive and, frankly, magical.

To assess the “holographic imaging” capability of any IEM, a good test track is “Hotel California (Live on MTV, 1994)” by Eagles. Here, the MEST III showcases an uncanny ability to separate the foreground (the band) and background (audience cheers) and place the latter in the surrounding environment. The audience’s cheers in the song’s opening feel astonishingly real in terms of distance, as if they come from my environment, rather than just inside my head. As the whole band starts, the MEST III accurately places the instruments around my head, with the singer floating in front and the audience noticeably positioned further back, creating a distinct sense of depth and spatial separation.

Soundstage imaging with games (CS GO Gameplay by Throneful) The MEST III provides an incredibly immersive gaming imaging experience that ranks among the most captivating I have encountered with an IEM. With this IEM, gunshots and footsteps sound as if they originate from the area surrounding my head, rather than being confined to a sphere within my head, which is a common characteristic of most IEMs. In this aspect, the MEST III operates more akin to earbuds, extending the sound around the head rather than restricting it to a mere left-to-right presentation.

The soundstage produced by the MEST III is not only expansive in width but also offers a remarkable sense of depth. Sounds seem to span from close to far in all directions, creating a strong sense of distance that enhances the overall listening experience. Moreover, it excels in accurately pinpointing the height of incoming sounds.

Resolution

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.

The MEST III impresses with its excellent technical performance, and this prowess extends to its resolution capabilities. Listening to “Jolene (feat. Dolly Parton)” by Pentatonix, I noticed a strong separation between voices, each one occupying its distinct space on the stage with ample “air” between them. This presentation allows for effortless tracking of individual voices, making it easy to discern each voice’s texture, nuances, and intricate details, rather than encountering smeared or blended voice lines.

The level of detail retrieval offered by the MEST III is truly outstanding. As previously mentioned, while listening to “Bach’s Violin Sonata No.1 in G Minor: Presto” by Kavakos, I could discern even the subtlest details, such as the breath and slight movements of the violin during quiet sections. This heightened sense of detail creates an immersive and authentic listening experience, making the recording feel incredibly real. Furthermore, the reproduction of the recording hall’s reverb showcases excellent detail, with the sense of the hall’s acoustic space seemingly highlighted with precision.

Pairing

The MEST III offers a volume level similar to the U12T across all of my sources, making it a suitable fit for portable gear. During my testing, I paired the MEST III with the FiiO UTWS5, a pair of Bluetooth earhooks, and was pleased to find that the IEM’s impressive staging performance remained uncompromised, even when using the AAC Bluetooth codec. Therefore, there’s no need to worry too much about what to pair the MEST III with, as it seems to adapt well to various setups.

However, one aspect that deserves attention is the choice of eartips. I discovered that the stock eartips didn’t work optimally with the MEST III, particularly in terms of sound quality. These tips seem designed to mimic the fit of a custom IEM, allowing the earpieces to sit as close to the concha of the ears as possible and eliminating any material in front of the nozzle. Unfortunately, pushing universal IEMs deeper into the ear canal can lead to a smaller perception of the soundstage. Consequently, my initial impressions of the MEST III weren’t very positive, mainly due to the stock eartips.

To achieve the best performance from the MEST III and fully harness the capabilities of the Bone Conduction Drivers (BCD) it’s crucial to ensure maximum contact between the earpieces and the ear concha. As a result, some eartips, like the Spin Fit CP145 and W1 that I typically prefer, didn’t sound as good as I had hoped before they push the earpieces far away from my ears. Eventually, I settled for the FiiO HS18 ear tips, which worked better for this IEM. All the descriptions provided above are based on my experience with the HS18 tips.

A brief note about the ear tips with holes on the hat that come with the MEST III: I found them to be unsatisfactory. Despite the earpieces fitting tightly in the ears, there was no air seal, resulting in a loss of all the bass and lower midrange of the MEST III. This made it sound tinny and emphasized the upper midrange, rendering it less enjoyable as an IEM.

Comparison and Rating

Tonality: 5/5 (Outstanding) - MEST III nails the type of tonality that I adore more and more nowadays: warmer and more “musical” without sacrificing the technical performance. In fact, I found my benchmark, the U12T, harsh and thin after a session with MEST III.

Percussion Rendering: 4.5/5 (Very Good) - MEST III has good bass, but not outstanding. It lacks a bit of the visceral and decisive dynamic swings that I expect.

Resolution: 5/5 (Outstanding) - MEST III fits confidently among the upper echelon. There might be a few IEMs out there that out-resolve the MEST III, but for mere mortals with limited funds like myself, these are as good as it gets.

Soundstage: 5/5 (Outstanding) - If I have a rank higher than 5/5, I would assign it to MEST III.

Special Comparisons

Comparisons: 64 Audio U12T

64 Audio U12T is old, but die hard. To me, any IEM within the A$3000 bracket must past the test “is it as good as U12T.” Listening to “Jolene (feat. Dolly Parton)” by Pentatonix, I noticed that the U12T had a noticeably leaner and colder sound signature compared to the MEST III. The U12T’s treble also felt harsher, introducing sibilance that the MEST III managed to avoid. Interestingly, the female vocals on the sides of the stage were less emphasized on the U12T, requiring more attentive listening to pick up those details. However, when considering the overall mix and separation, both IEMs appeared to be on a similar level in terms of detail retrieval.

When I shifted my focus to “Bach’s Violin Sonata No.1 in G Minor: Presto” by Kavakos, I observed more noticeable differences in the technical performance of the MEST III and U12T. While both IEMs delivered a similar level of nuances and details, the reverb trails were more prominently highlighted on the MEST III. This created a stronger and more encompassing effect, forming a dome of sound around the head, which the U12T felt flatter in comparison during A/B testing. Tonality-wise, the U12T was less colored, presenting the violin with a truer-to-life sound but potentially rendering it less enjoyable to some listeners.

Determining which IEM is better might come down to price considerations, as used U12T units can be found at a lower cost than the MEST III. Additionally, the U12T’s established reputation and staying power might influence its resale value, which can be a significant factor for many users.

Comparisons: AFUL P8

The comparison between the AFUL P8, a $380 IEM, and the MEST III, a multi-kilobuck IEM, might raise eyebrows due to the price difference. However, the market for reasonably-priced IEMs has seen significant advancements in technical performance, rapidly closing the gap with old kilobucks like Andromeda 2020. Hence, I wanted to gauge the gap between the P8 and a modern high-end IEM like the MEST III.

In direct A/B tests, the difference between the two was apparent. Listening to “Jolene (feat. Dolly Parton),” I quickly noticed an extra level of nuances and details when switching from the P8 to the MEST III. The P8 also exhibited a noticeably leaner and colder tonality compared to the MEST III.

Where the gap in resolution didn’t bother me too much, given the already impressive resolution of the P8, the disparity in soundstage imaging was more significant. When listening to “Bach’s Violin Sonata No.1 in G Minor: Presto” by Kavakos, the P8 felt more two-dimensional, lacking the sense of sitting in front of a dome of sound created by the room’s reverb. In contrast, the MEST III managed to create the illusion of being in the same room as the violin, surrounded by a dome of reverb around my head. The MEST III’s rendering of the violin also appeared more nuanced and textured compared to the P8. The only advantage the P8 held was a truer-to-life tonality for the violin, though some might find the MEST III’s more colored tonality to be more enjoyable.

Conclusion

In my journey through the audio hobby, I’ve frequently experienced high expectations, followed by bitter disappointments. However, my encounter with the MEST series was a delightful and rewarding experience.

Pros:

• Holographic Soundstage: The sense of space and directionality was outstanding, making the listening experience truly captivating.
• Top-notch Resolution: The MEST III showcased exceptional resolution. Every instrument and voice felt clear and well-defined.
• Neutral-warm Tonality: I appreciated the coloured tonality of the MEST III. The vocals were natural and rich, and the instrument timbres felt enjoyable yet authentic.
• Energetic yet Controlled Treble: The treble performance of the MEST III struck a good balance between energy and control. The highs were engaging and provided a good level of sparkle without becoming harsh or fatiguing.

Cons:

• The Dynamic Could Be Improved: While the MEST III delivered a satisfying dynamic performance, I felt that it could be enhanced to provide a more visceral and impactful experience.
• The Stock Cable is Too Stiff: The stock cable provided with the MEST III proved to be overly stiff, affecting the overall usability and comfort of the IEM.
• The Stock Eartips Hinder Sound Quality: The stock eartips compromise the soundstage and overall sonic experience, making tip-rolling a necessity.
• Price Hike from MEST II