Marcus reviews the Unique Melody Mest Jet Black, a hybrid dynamic, quad BA, dual EST, and triple bone conduction driver IEM. It is currently priced at $1999 for the universal version and $2299 for the custom format (with cables).
Disclaimer: This sample was sent to me in exchange for my honest opinion. Headfonics is an independent website with no affiliate links or partnerships. I would like to thank the team at Unique Melody and Musicteck for their support.
Click here to read more about the Unique Melody products previously reviewed on Headfonics.
This assessment follows our current scoring guidelines, which you can read in more detail here.
The Unique Melody Mest Jet Black is technically the 4th release of the MEST IEM series and comes in universal and custom formats, with our sample being the custom version.
It also stands as their IEM with the most complex driver configuration to date, with a mix of dynamic, BA, EST, and two different types of bone conduction drivers.
And yet, like previous MEST monitors, they’re not their most expensive at $1999 for the universal and $3000 for the custom format. For that reason, they are often cited as a sweet spot for UM monitors, offering excellent value for the performance.
I have previously covered the Mest MK1, MKII, and MKIII CF custom versions, so it made sense for our readers to continue with that trend, given that this type of review is harder to find than the universal format.
As always with UM custom formats, the MEST Jet Black version is priced a little higher than the universal version, and in this specific instance, it uses slightly different materials.
I typically find custom IEMs sound a little different from the universal version since they do not use ear tips, so bear that in mind when reading my full review below.
Features
The Unique Melody Mest Jet Black is a complex hybrid 10-driver IEM (custom and universal) using a mix of dynamic, BA, EST, and bone conduction drivers.
The precise driver grouping is a single dynamic for the lows, dual BA for the mids, dual BA for the highs, and dual electrostatic drivers for the ultra-highs using a passive 4-way air conduction crossover.
Unique Melody does not mention the type or size of dynamic driver they are using for the Mest Jet Black, but I would presume it’s 10mm, since all previous MEST generations have used that size.
The big focus here, though, is the full-frequency bone conduction system with no less than 3 bone conduction drivers of two different types: composite BA and piezoelectric.
The Mest Jet Black uses 2 composite BA bone conduction drivers for the lows and mids from roughly 300 Hz up to 3 kHz, and a single piezoelectric bone conductor that starts at about 500 Hz but peaks at 4-8 kHz upwards with a separate 2-way crossover point at around 4 kHz.
With an impedance rating of 16Ω and an SPL of 106 dB @1kHz, the Mest Jet Black is an easy IEM to drive from either a quality dongle or DAP. However, as detailed in my synergy section on page 2, it can scale with decent power.
Design
Since it is a custom design, the aesthetic and shape will be unique to your ear and preference. UM uses some incredible materials, including titanium and carbon weave, with the Mest Jet Black universal using ceramic for its enhanced isolation and acoustical performance properties.
In this instance, I believe the custom version shell is resin-based, but since it is shaped from a 3-D scan of your ear, the passive isolation performance is still top-notch.
This particular Mest Jet Black sample is based on UM’s custom color palette and is called Z18 Ambilight Red. This design was applied to the plate and the main shell to give it a cohesive design look, which is a style I prefer over two-tone approaches.
The aesthetic is a beautiful blend of red stripes and blue background in a nebula or lava-type swirl finish, giving it a darkish, dreamy overtone, complete with the gold flower-petal vent at the corner of each faceplate.
You can also add various artwork on top, such as the UM logos or graphical design from your collection, but in this instance, mine came with neither, giving it a lower non-branded profile.
This particular Mest Jet Black custom-designed form factor is also a long-spout finish. Some would call it a “Pro” nozzle as it is a bit thicker and extended a bit deeper into your canal. This keeps it safe during vigorous movement.
I do not vigorously move, but I have found this design choice to offer enhanced isolation and reach closer to the 2nd bend in the ear canal, thus improving the sound quality.
Comfort & Isolation
As with any properly made custom IEM, the Mest Jet Black fits my ear perfectly, creating incredible levels of passive isolation and is superior to any ANC TWS.
However, this particular custom version of the Mest Jet Black fits a little differently than the previous MKIII CF version due to the thicker, longer nozzle.
The additional girth provides a more secure fit in my ear compared to the MKIII CF, but at the same time, creates a little more pressure in the ear canal. If you are sensitive to pressure, I would advise requesting UM to shave a little off the nozzle thickness to create a more relaxed fit.
Another noticeable change from the MKIII CF passive isolation performance is a little bit of wind noise, similar to the experience from an ANC headphone or earbud.
I suspect this noise is being captured and slightly amplified by the petal vent on the top plate, something which the MKIII CF does not have or suffer from. If you place your finger over the vent, the sensation is gone.
On a calm day or indoors, this might not be an issue, but for outdoors or near electric fans, you might want to ensure you are not in the direct path of the wind being generated.
Stock Cable(s)
This is where things get a bit creative. The Mest Jet Black can be bought without any cables for $300 off the list price.
If you want a cable, you have 2 options with two different tuning effects: the warmer UM Dreamy, a UM-branded PW Audio collaboration, and the more neutral UM Jet Link, a collaborative design with Effect Audio. Both cables are made from copper but have different external designs and wiring geometry.
The UM Dream is a 4-wire design composed of 24AWG OCC copper with a sevenfold pipe structure or seven twisted cores. The Jet Link is a slightly smaller 4-wire 26AWG OCC copper wire, also with a seven-core twisted structure.
Both cables are finished with a black PVC jacket, though the Dream has a matte finish and the Jet Link has a glossy finish.
The biggest physical difference is the barrels and connectors. The Dreamy’s bulkier and curvier gold-finished barrels are consistent with the UM design language from their previous M1/M2 cables, with their clean cut lines and the easy grip form factor on the jack.
The Jet Link has a bit more dazzle about it with smaller but denser barrels and off-centered 3-dimensional motifs. Of the two, the Jet Link stands out a bit more with its more intricate barrel designs.
That perception is reinforced with the more pliant handling from the Jet Link cable. The matte PVC jacket on the Dreamy feels a little stiffer, and its memory coating is a little thinner when placed around the ear.
Packaging & Accessories
Since this is a custom version of the Mest Jet Black, you will not find any ear tips, and because it is a sample unit, it came packaged in the universal format box.
Typically, retail-ready UM customs come in fairly small compact boxes, but the universal format box is more substantial with plenty of graphics and branding on it.
Size matters, though in terms of display, with a slightly revised and longer edition of their long-standing blue zippered carry case holding the drivers and cable (if a cable was purchased) neatly on display on top, and all the accessories hidden underneath a lower protective layer.
UM has packed a cleaning cloth and themed leather organizer strap with a matching petal design for the latch, though I find the strap a little bit big and loose for the associated cables.
It’s an attractive design with a quality leather finish. I suspect that if you bought both cables, it could handle both just fine.
Click on page 2 below for my sound impressions and recommended pairings.
