Unique Melody MEST Jet Black Review – Bright & Brilliant

Pros –

Quality accessories, Indestructible build quality, Fantastic cable from PW Audio, Excellent resolving power and staging, Highly revealing and detail forward, Included ear tips offer both analytical and balanced tonalities, Excellent separation

Cons –

More ear tip dependent fit, Bass can lack warmth at times, Unforgiving tuning

Verdict –

This is an IEM purpose-built for technical performance above all else, with innovative bone conduction driver tech serving to enhance soundstage width and separation.

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About Unique Melody –

Unique Melody is one of the original manufacturers of custom in-ear monitors in Guangdong, China, having been established in 2007. The brand has achieved renown for their innovative hybrid designs that push the boundaries of audio technology. They now offer a wide array of custom-fit, universal and even TWS models stretching from the midrange to TOTL price points.

Introduction –

The MEST series is one of UM’s most popular for its versatile tuning and appealing price point. What unites each IEM is a hybrid driver setup and use of bone conduction drivers, with the original MEST representing one of the first to market. Jet Black is UM’s 4^th generation model and promises to further extend BCD technology in addition to using a novel zirconia ceramic shell. It has been designed with tonal accuracy and technical ability first and foremost in what UM considers its most advanced hybrid architecture to date. To this end, Jet Black implements a DD woofer, dual BA mid and dual BA highs with 2 electrostatic ultra-high drivers. The bone conduction system uses its own hybrid setup with 2 composite BA BCD’s and a  piezoelectric BCD to enable the bone conduction system to cover the entire frequency range. Jet Black is an incredibly complex IEM from a brand with enough experience to pull it off.

MEST Jet Black is available for $1,999 USD at the time of writing. You can read more about it and secure one for yourself at Unique Melody!

Disclaimer –

I would like to thank Sean very much for reaching out to organise a review of the MEST Jet Black. All words are my own, and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.

Contents –

• Page 1: Intro, Unboxing, Design
• Page 2: Sound and Source Pairings
• Page 3: Comparisons & Verdict

Specifications –

• Driver: Dd Low, 2 BA Mid, 2 BA High, 2 EST Ultra High
• Bone Conduction Driver: 2 BA Low/Mid, 1 PZT High
• Impedance: 12.6 Ohms
• Sensitivity: 106 dB
• Crossover: 4-Way Air Conduction, 2-Way Bone Conduction

Behind the Design –

Air Conduction

Fancy vernacular for your run-of-the-mill hybrid audio setup, UM nonetheless offers an advanced tribrid setup that would impress alone. This comprises a dynamic driver woofer, dual midrange BA’s, dual BA tweeters and dual Sonion EST super-tweeters. These drivers are united by a 4-way crossover. Though not labelled on UM’s marketing, you can also see the use of waveguides on the BA drivers, which will aid phase coherence and reduce distortion further.

Bone Conduction

UM spent 6 years developing a hybrid BCD system that covers the entire frequency range. Jet Black implements a 2-way BCD system that implements 2 composite BA drivers for the lows and mids, in addition to a traditional piezoelectric BCD. This permits what UM calls full frequency compensation, with the bone conduction system augmenting the entire range of air conduction in addition to lowering distortion by delegating frequencies to specific drivers. UM promises enhanced speed and bass impact, smoother frequency range transitions and improved layering and staging.

Zirconia Shell

As a dentist, Zirconia is a material I’m very familiar with. It offers excellent mechanical properties that are further enhanced by a 1600 °C firing process. UM mills whole blocks of zirconia with a diamond-tipped CNC lathe, which should speak to the hardness and scratch resistance offered by the shells. While the mention of ceramic may give some pause due to fear of cracking or breakage, Zirconia is more crystalline in its makeup, which makes it highly fracture and shock-resistant, hence its common biomedical applications. Cracking is highly correlated with micro scratches on the surface, which UM addresses with a multi-step hand-polish process to deliver a flawless, smooth and strong piano black finish. UM reasons that the hard ceramic offers excellent tactile feel and durability in addition to strong passive noise isolation. The material also provides excellent acoustic properties and resonance control.

UM Dreamy Cable

UM has co-developed a bespoke cable for MEST Jet Black alongside industry powerhouse PW Audio, dubbed Dreamy. This is a single-crystal OCC copper cable with a 24 AWG thickness and 4 conductors. The copper conductors feature a seven-fold pipe structure and undergoes natural annealing for 1 year. Unfortunately, I couldn’t find any information online that explains the specifics and advantages of this structure in English, but rest assured, the physical quality of the cable is excellent. UM outfits Dreamy with metal connectors in matching gold to suit the earpieces themselves.

Unboxing –

Unique Melody provides a premium unboxing experience. The actual packaging is quite simple, but more has been invested into the accessory set, which I have no complaints with. Upon opening the black hard box, the buyer is greeted by a goatskin leather zip case with soft suede interior. It is moderately sized and would fit a small DAP or DAC/AMP in addition to the earphones. It also has an integrated cable winder and two compartments that separate the IEM housings to prevent scratches. A top pocket contains some papers and can be used to store extra ear tips, etc. In addition, two mesh drawstring bags protect each earpiece. Below are the ear tips, with UM providing 3 types. The blue heart standard silicone tips come pre-installed and are available in 4 sizes. There are also two kinds of transparent thermoplastic silicone tips. They have a shorter stem and offer a deeper fit depth which should result in less brightness – more on this later.

Design –

The first thing you’ll notice on Jet Black is its superb in-hand feel. The zirconia ceramic shells offer an awesome sense of density and solidity like few others. While the high-polish finish is a fingerprint magnet, they haven’t picked up so much as a scratch over my past few weeks of testing due to the hardwearing material choice. Jet Black also looks distinctly different to previous MEST iterations due to its adoption of angular brushed aluminium faceplates. The aesthetic is a hybrid between ornamental and mechanical, with exposed fixing pins and a matching gold-anodised flower vent. In my opinion, an entirely zirconia shell would have been even more jaw-dropping; however, I’m sure this arrangement has an acoustic underpinning that UM may not have discussed in their marketing material.

MJB uses my preferred 0.78mm 2-pin removable cable system, which is ubiquitous across the market. The Dreamy cable is of excellent quality, which doesn’t surprise given its PW Audio underpinnings. Specifically, it has a supple satin black jacket that has zero memory and coils wonderfully for storage. The 4-wire braid resists tangling well and reduces microphonic noise when combined with the over-ear fit. The ear guides are pre-moulded and offer good comfort and stability for my ears. Dreamy terminates in a 4.4mm balanced connector, unfortunately, with no modularity. However, the overall quality and ergonomics offered by this cable are top-notch. It feels well-constructed and durable without becoming overly cumbersome.

Fit & Isolation –

Jet Black offers a shapely and smoothly contoured shell design. They aren’t overly tall but are quite wide, so don’t expect a low-profile fit. Despite having some heft, I didn’t find MJB uncomfortable, nor did they produce hotspots due to their smoothly formed design. With that said, the nozzle angle didn’t sit well with my ears; I had to rotate the housings anticlockwise until they were pressing quite firmly against my concha to get a seal.  I found them more ear tip sensitive than most IEMs, as a result, though potentially this was intentional to allow the shells to contact the outer ear cartilage to optimise BCD function.

The standard blue heart tips would collapse in my ears, losing seal, but the transparent tips both provided a more confident and reliable seal during my testing. Despite the dense shell design, MJB is vented, and passive noise isolation is just above average. Some driver flex is apparent, but it didn’t affect performance during my testing. They are suitable for commuting and public transport, boasting sound noise rejection in noisy environments. This works well in tandem with their more revealing tuning and means you can enjoy a more consistent sound profile when on the go and when listening at home.

Next Page: Sound Breakdown