Unique Melody UM Mest Indigo

Another MEST have, before it’s gone.

PROS: updated quadbrid driver design (DD/4BA/4EST/dBC), powerful dynamic bass impact, natural-detailed hi-res tuning, new 3D Sapphire Pinewood faceplate, replaceable nozzle filter, updated PWA Copper M3 cable, AZLA Xelastec eartips, custom Dignis leather storage case.

CONS: higher price than Mest MKII, the sound is eartips dependent, universal only.

The product was loaned to me for the review purpose in exchange for my honest opinion.

Manufacturer website:  Unique Melody.  Available for sale from MusicTeck.


Every time I post a teaser about a new audio product, I get flooded with requests of early impressions and to hurry up with a full review.  This time, I got flooded with the same even before I received the product.  As a matter of fact, I decided to borrow the latest Mest Indigo for review because a lot of my readers asked me to compare it to Mest MKII which I reviewed early this year.  I still can’t get over how popular Mest has become.  Per my own personal preference, I found the 2nd gen version of Mest to be an upgrade over the original.  Yet, many of the people who are pinging me now, got both OG and MKII and don’t want to part with either one.

So the big open question, what is Indigo?  Is this Mest MKIII?  Is this a Special Limited Edition Mest MKII with a new faceplate?  Or, is this an all-new IEM that just carries Mest DNA?  I honestly thought this is going to be one of my shorter “in-a-snapshot” type of comparison reviews with a focus on Indigo vs MKII.  Shorter write-up is where I’m heading now due to the amount of review samples I receive and limited time I have to write long reviews.  But after a few days of burn in, as I started listening to Indigo, this latest creation from UM put me under its deep-blue spell, and I decided to finish the full review which I’m sharing with you today.


Unboxing and Accessories.

The unboxing experience of Indigo is very similar to MKII, plus a few additional updates.  It still features the same giftbox quality storage box with UM logo on top.  Once a magnetic top cover is lifted, you are presented with a deep blue leather case, also labeled with UM logo.  In the original Mest you had to remove the case to get to the bottom of the box so you can access the remaining accessories.  With Indigo, just like MKII, Unique Melody added a drawer at the bottom which slides out from the side to give you an easier access to the rest of the included goodies.

You should also expect similar accessories as MKII, though a few have changed.  For example, you will still find Dignis storage case with a zipper top, roomy enough for your IEMs, cable, and other extra accessories.  Inside, it has a flexible velcro partition so you can separate shells and the cable.  This is a premium brand name product, not some filler.  The color of the case is deep blue to match Indigo color theme, and the top cover has the same design as their Fabled Sound/FuSang flagship iems, with a layered velour corner insert, making it more premium and unique.

Furthermore, you will find a new PWA (Peter Wong Audio) brand name copper cable, which I’m going to talk about later.  Next, a plastic warranty card (the size of a credit card), with a printed S/N, website address, and a service email.  There is a grey cleaning clothe/pad to keep those shells fingerprint free.  Then, you have a complete set of eartips with blue-heart silicone S/M/L, and popular brand name AZLA Xelastec SS/MS/M eartips.  Those provide a superior isolation and a very secure fit.  There was also a leather cable storage/organizer clip.  From what I have seen on Musicteck page, the Magnetic Earphone Clip (MEC) for cable storage and foam eartips are included with Indigo as a bonus accessory package, available to first 50 customers.

Just like with original MKII, you will find a lot of brand name popular accessories here, Dignis custom leather case, PWA copper cable, AZLA Xelastec eartips, etc.  When it comes to accessories, UM likes to spoil, and we are not talking about the overall quantity, but the actual quality and usability.



Looks like UM decided to continue with PWA collaboration (Peter Wong Audio – PWA), and for this limited release Peter cooked up a new copper cable.  Labeled as UM Copper M3, it is all new cable with 22AWG gauge high grade OCC copper wires.  The cable features 4 wires with PVC shielding and nylon protective sleeve.  The 4 conductors have a loose braiding between the plug and y-split, and twisted in pairs going up to IEM connectors.  The original MKII cable was thinner, 24AWG wire gauge, while having a similar PVC/nylon shielding and sleeve but just in black.  Indigo cable has thicker copper wires, which should decrease the resistance of the cable, and the sleeve has a deep blue color to match the Indigo color theme.  And, thanks to this sleeve, the microphonics is reduced down to minimum.

Furthermore, the cable hardware has been completely redesigned and updated.  Now, it features bronze metal alloy finish, the same as the faceplate frame of Indigo.  The plug, which could be selected in 2.5mm, 3.5mm, or 4.4mm termination (Musicteck lists 2.5mm and 4.4mm, have to ask separately about 3.5mm) features an all-new hexagon shaped housing with a round shaped notched end, custom square y-split with an oval-shaped end and matching oval-shaped retractable chin-slider, and a matching bronze metal 2pin connector housing with UM logo facing outside.  You will also find a pre-shaped heat-shrink earhook.

This is not a cheap stock cable with just pretty hardware.  The cable feels solid, durable, relatively soft, non-microphonic, with a beautiful matching hardware, and from one of the top brand name cable makers.  The Copper M2 cable was selling by itself for about $500, and I’m sure this one is more expensive considering thicker wires, higher grade pure copper, and custom hardware.


There is a very good reason why UM decided to call this new limited edition release MEST Indigo.  It has a lot in common with the original and MKII releases of MEST.  And at the same time, it has so many changes that take it to a whole new level.

First of all, a new “facelift”.  That is probably the biggest and the most noticeable change you will see before even putting these little gems in your ears.  The original Mest/MKII carbon fiber lightweight shells infused with gold flakes looked nice, but the look itself was more modest.  The new Indigo shells are gorgeous.  The shell itself now features Indigo carbon fiber material with an infused blue accents, but the focus is on the faceplate that features 3D Sapphire Pinewood insert.  The color and the pattern are mesmerizing, surrounded by a bronze alloy frame around the edges.  The same bronze alloy metal finish is featured in hardware of the new UM Copper M3 cable, along with deep blue cable wire sleeve to match the Indigo theme of the design.

The overall shape and the size of Indigo shell is nearly the same as Mest MKII.  But there are a few important changes.  In order to maintain a solid look of the faceplate, the metal-plated venting port is no longer in the corner of faceplate, moved to the side, just a small pinhole vent at the top of the shell closer to the faceplate.  One big change is removable and replaceable nozzle mesh filter.  If that mesh screen gets clogged or broken in Mest/MKII, you have to send it for a repair, while in Indigo you just unscrew the top and replace it with included spares.  This also opens a door to offer a different pattern mesh filters in the future, something that can alter the sound and act like a real sound filter, if UM ever considers that.


Inside, the driver config has been updated with addition of 2 more EST drivers.  Now, Indigo features a configuration with a total of 10 drivers grouped in 4 types: DD, BA, EST, and Bone Conduction, a 4way quadbrid design with a 5-way crossover, including DD bass driver, 2BA mid drivers, 2BA treble drivers, 4EST ultra high drivers, and one full range dBC dual sides Bone Conduction driver.

Similar to MKII, and in contrast to a single side BC driver in OG Mest, Indigo also uses double sided piezoelectric bone conduction driver which is placed in between two supporting plates and visible underneath of the faceplate.  At the center of that dBC driver is the vibration board covered by ceramic coating on both the front and the back.  Also, this dBC bone conduction driver now has a larger contacting area with the shell and has a wider effective frequency response range from 500Hz to 20kHz, in comparison to OG with BC that covered 1kHz to 16kHz.  It is hard to zero into dBC effect and I don’t want to speculate since we can’t compare Indigo with and w/o dBC.  But the 3D precision of imaging and multi-dimensional effect of upper frequencies makes me wonder if it is part of dBC contribution.

The fit.


Page 2 – Sound Analysis, Eartips selection and Cable pair up.
Page 3 – Comparison, Source pair up, and Conclusion.

12 thoughts on “Unique Melody UM Mest Indigo

  1. Have you been interested in the Elysian Acoustic Labs Annihilator 2021?

    I’ve been interested in this IEM because of its superior treble extension in the frequency response.

    I mean, some reviewers out there said that the Annihilator 2021 makes other IEMs thus far a laughing stock because other IEMs have a poor EST implementation like having an upper treble roll-off, not having enough sparkle, too dark, etc.


    1. Sorry, no plans to review Annihilator or X, Seems like this one is a mixed bag of impressions, people love how well it renders treble, but not the mids. It felt like FOTM. Btw, which review are you referring to? Can you provide a link? Curious about it.


      1. It was Precogvision’s impressions on the Annihilator, here’s the link: https://www.head-fi.org/threads/precogs-iem-reviews-impressions.937468/page-40#post-16351838

        But I think the Annihilator that Precogvision got is the demo version or the Pre-2021 edition because the cable was different.

        Here’s the picture of the Annihilator that Precogvision took: https://www.head-fi.org/threads/precogs-iem-reviews-impressions.937468/page-40#post-16350442

        Here’s what the Annihilator 2021 cable looks like, it comes with Liquid Links Martini as a stock cable: https://www.facebook.com/elysianacousticlabs/photos/a.1455532574536383/4123619397727674/

        Here’s the picture of the demo version of the Annihilator that crinacle took: https://crinacle.com/2020/01/14/cliffnotes-elysian-annihilator-dio-the-exception/

        And also, the mids on the Annihilator 2021 were flatter compared to the Annihilator Pre-2021, sample 2, which is more V-shaped: https://crinacle.com/graphs/iems/elysian-annihilator-dio/

        I still don’t know if the Annihilator 2021 were thin though.


  2. Hi Twister6, would like to know if you can compare U18t to the UM Melody Indigo, my local dealer still have some spots left for pre order of the indigo. I am kind of interested but would like to know your take vs U18t. Thanks alot.


    1. a very different tuning where U18t has flatter bass, more forward and brighter mids, and brighter treble, while Indigo has more elevated dynamic bass, less forward and smoother mids, and not as bright treble.


      1. Thanks for your reply, I currently find U18t bass is lacking to my taste with M20 module (with M15 to me is like bass is not even there). I listen to alot of female vocals that get quite high in the treble, I am sensitive to treble and sibilance. I love the sound of my HD800s and Hifiman Arya Stealth. My Focal Stellia sounds weird with very shouty female vocals but I like the bass amount on the Stellia and the soundstage is quite nice.

        For an iem with good depth, width, great bass, great details and biggest soundstage depth and wide. What do you recommend? Basically looking for a HD800s sound with more bass in an Iem. Thanks alot Twister6.


      2. Not familiar with Hd800s, only heard it needs a powerful amp to make it sound great. Thus, would be hard to recommend equivalent iems to any of the headphones your are using. Sorry.


  3. Hi Twister6,

    How would you compare the Indigos to the 64A Nio or U12t? I’ve got my choices down to these three but I’m really torn over which one to go for and haven’t seen any reviews where a comparison is made between these specific models.


    1. Have to go by memory since I don’t have Indigo with me anymore, it was on loan. It’s not an easy decision, but each one offers something different and unique. If you want the biggest soundstage with the best imaging, it’s Indigo. The biggest bass impact Nio, the a great texture analog bass is Indigo since U12t BA bass is good but not the same as DD. The most balanced tuning U12t, probably the “safest” tuning that will work with any genre of music. Ability to tweak the sound, Nio/U12t with their apex modules and optional atom modules from fir audio. The smoothest treble, probably Nio, while Indigo will give you more micro details and more energy in treble. The most tech per square inch and the most comprehensive set of accessories (PWA copper balanced cable, Dignis leather case, Xelastec and Comply tips) – Indigo 😀


      1. Twister6,

        Thank you so much for your response, I think. haha You have given me a lot to think about. Using what you wrote the Indigo checks the the most boxes, and they look sexy. Yet, one comment you made has me really on the fence. The U12T has the “safest” tuning that will work with any genre of music. I listen to a lot of different genres. I think musicals and opera are the only two I can outright rule out. Just not my thing, but everything else is fair game for me even if it’s just a song here or a song there. That complicates my decision greatly because I do appreciate good bass and would have preferred to stick to an IEM that has a DD in it. Precog made some interesting comments in a YouTube video about the U12Ts saying they have the least amount of compromises and he’s a basshead. Maybe the U12Ts will fill the bill with the right APEX or ATOM XL module. Or then again there’s the Indigos.

        Or…. maybe if I weren’t so concerned about the size of them and fitting in my ears comfortably I would almost wonder if I should just get the EE Odins and be done with it, because two DDs is better than one right? haha I wish there was a place where I lived that had these so I could test all of these IEMs out and make an informed decision.

        Thank you again for responding and weighing in on these IEMs. It is much appreciated to finally have at least one person’s comparison of these IEMs from experience they have or had with them. 🙂


  4. Hi Twister6,
    How would you compare Indigo to EE Odin in general, especially in bass and treble area ?
    How is the fitting in your ear compared to EE Odin ? Is it more comfortable ?

    Many thanks in advance.🙏


    1. I don’t have Indigo anymore, was on loan from Musicteck for review. In bass area, Indigo has deeper extension with more rumble and stronger impact, while in treble the Odin has more sparkle and air. So, when it comes to tuning, they are more complementing than competing. The fit will depend on your ear anatomy. I don’t have a problem with either of these, and found both to be comfortable.


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