Unique Melody--The Multiverse Mentor Flagship IEMs

UM Multiverse Mentor - The new IEM benchmark?
Pros: - Magical midrange and vocal performance
- Great tonal balance across all frequencies
- Excellent BA bass, in conjunction with the BCD
- Incredible technicalities including speed, resolution, imaging, and layering
- High quality, and ergonomic PW Audio cable
- Comfortable for long listening sessions without fatigue or pressure build-up
Cons: - BA bass (specifically for DD bass fans)
- High cost
- Some slight visual imperfections on the shells
IEM driver technology continues to be one of the most exciting and innovative spaces in the headphone audio market. Over the past few years we’ve seen countless designs utilizing dynamic drivers, balanced armature drivers, piezoelectric drivers, bone conducting drivers, and hybrid designs containing various combinations of the above.

Bone conduction technology is different from the other driver technologies that move air, in that it passes vibrations through the bones in the jaw and skull, directly into the inner ear. In a sense, this means that the sound bypasses the ear structure and the sound is heard from inside the ear, instead of outside.

Guangdong-based Unique Melody are now one of the most well-known manufacturers of IEMs and like many current IEM manufacturers, can trace their roots back to the hearing aid business. They were also one of the first to introduce bone conduction drivers into their products. The Unique Melody MEST and its successor, the MEST MKII were very well received by the Head-Fi community. More recently, Unique Melody continued with various bone conduction designs and had three limited edition flagship products in the Mason Fabled Sound and FS Le Jardin, and the Red Halo, that all used a hybrid design of 12 balanced armature drivers and a full-range bone conduction driver.

The Multiverse Mentor is Unique Melody’s newest flagship product in the Mentor Series and retails for $4,499 for the universal model, and $4,999 for the custom model. During CanJam SoCal 2022, I was fortunate enough to stop by the MusicTeck booth on the Sunday afternoon before the show closed in order to hear the Multiverse Mentor, paired with the fantastic HiBy RS8 digital audio player. It’s always an eye-opening experience when experiencing truly cutting-edge products that are pushing boundaries for the first time, and the MM (and RS8) certainly fell into this category.


According to Unique Melody, the new Mentor features a brand new Frequency Shift Piezoelectric bone conduction driver that was specifically developed for the entire hearing frequency range of human ears. To ensure the driver’s performance, a conductive palladium slurry with high temperature resistance is applied to the vibrators, and a pure copper substrate is added on top of a double-sided ceramic layer. The performance of the driver is also optimized by adjusting the internal structure of the cavity, which also reduces the vibrations sense and increases the comfort.

The Mentor has a 5-way crossover design which features 4 bass, 2 mids, 2 mid-treble, and 4 treble balanced armature drivers along with the bone conduction driver. The Mentor comes with a lovely PW Audio cable with 26AWG copper and silver-plated copper wires. The cable is covered in a soft nylon material, and independent shielding that PW Audio dubs “Deep of Universe''.

I’ve now had a chance to spend several weeks with the Multiverse Mentor and have used it predominantly with the HiBy RS8 DAP, the EarMen Sparrow dongle DAC, as well as with the dCS Lina DAC (set at 2V output), and AMP (set to low gain).

Unboxing and First Impressions
The Mentor ships in a relatively small shrink-wrapped silver outer box. Opening the outer box reveals a silk-screened inner box which opens with a latch system and also contains a shelf of included accessories. The Mentor itself sits inside of the vegan leather case, which itself is wrapped in a white cloth drawstring bag. While the packaging is not what I would consider “luxurious”, it is very professional and imparts an understated feeling of quality.



The accessories include a set of Azla Xelastec ear tips, cleaning materials, and replaceable metal mesh filters. The case, while rather large, is of a high quality and appears to be made by a particularly well-known and popular manufacturer from the Republic of Korea.



Looking at the earpieces themselves, the Multiverse Mentor is made from a Carbon Fiber blue shell, with a Ceramic Frame holding the Bone Conduction Driver, and is finished with a Banksia Seed Faceplate. The Banksia wood in person gives the Mentor a darker brown appearance with splashes of purple that are accentuated when hit with direct light.

The custom-designed cable from PW Audio is a deep blue color that matches the blue ceramic frame of the Mentor almost perfectly. It’s a a 4 wire, 26AWG silver-plated copper cable called “Deep of universe” that is terminated in a 4.4mm balanced pentacon plug. Overall, the cable seems to be of very high quality and while it’s quite large and thick, the ergonomics are very good, with the cable folding/wrapping, and unwrapping nicely.

I found that the relatively small size of the earpieces made for a comfortable and ergonomic fit. Additionally, with a vent in each earpiece shell, there was no perceptible pressure build in my ears, so extended listening sessions were overall very comfortable.


I used the Mentor in three different configurations as follows:
  1. HiBy RS8 R2R DAP, medium gain, Turbo enabled
  2. dCS Lina DAC and AMP, 2V setting, low gain enabled
  3. EarMen Sparrow dongle DAC
My primary configuration was using the HiBy RS8. This DAP has an R2R architecture and is rather smooth sounding while maintaining excellent levels of detail. In order to see how well the Multiverse Mentor could scale, I also used together with the dCS Lina DAC and AMP which added another layer of detail retrieval and transparency while maintaining a perfectly black background. Finally, I used the Mentor with the EarMen Sparrow dongle DAC connected to my Steam Deck for some handheld PC gaming. In both of the latter use cases, 4.4mm adapters were used as needed.

The Multiverse Mentor competes at the highest level of flagship IEM territory and is positioned to take on the likes of the Aroma Jewel, Oriolus Trailli, and other top tier offerings.

Sound Impressions
I’ve been listening to the Mentor almost exclusively for the past several weeks and continue to be deeply impressed. These are among the finest IEM’s I’ve ever experienced and blend a combination of technical mastery and are tuned almost perfectly to my personal listening preferences. Foremost is a great sense of tonal balance across the frequencies along with truly magical midrange. In particular, vocals sound rich and lifelike and have a certain intangible quality that makes them come across as incredibly natural.

While some may lament that BA bass cannot overcome certain shortcomings, I felt that the Mentor’s bass, enhanced by the Bone Conduction Driver, certainly provides a great bass experience with impact and slam when called upon. And while it’s not quite equivalent to dynamic driver bass, I never really thought anything was lacking. Of course, there are also those who prefer BA bass in that it also can be less fatiguing to listen to. As with most things in the hobby, YMMV.

The Multiverse Mentor’s treble is also extremely well tuned. It’s highly resolving and is able to extract the micro details, with the sparkle and shimmer when called upon, but it’s tasteful and never overdone. I’m fairly sensitive to treble sibilance and listening fatigue in general, yet I never felt this while listening to the MM.

The MM is an absolute technical monster. It’s resolution, soundstaging, layering, and overall speed are “best in class” impressive, and are really pushing the boundaries of what’s possible in an IEM today.

Unique Melody has really hit it out of the park with the Multiverse Mentor. While it’s impossible to “crown” a single IEM as being best in its category, I can unequivocally say that it's perhaps the most well balanced IEM I’ve personally experienced, and fits my personal listening preferences to a tee. As an all-arounder with flagship level technicalities, the Multiverse Mentor has a magical midrage, a highly detailed yet non-fatiguing treble, and among the best BA bass I’ve ever heard, aided by the Bone Conduction Driver. Tying it all together is a laser-focused set of technicalities which I’ve rarely experienced in an IEM. The Unique Melody Multiverse Mentor has my highest recommendation and is a must-audition for anyone in the market for a flagship IEM.

Last edited:
Midrange is definitely magical. One of the top iem you can listen
I wonder what the cost of the drivers and materials is - maybe $500 at most?
Totally agreeing with all the points in the review. The technicalities are out of this world. Usually technicalities mean fatiguing listening to me. But the MM manages to be one of the most technically resolving iem yet remaining easy to listen to. It’s really a “just-one-more-track” kind of iem for me. Homerun for sure!

Scuba Devils

Headphoneus Supremus
Unique Melody 'The Multiverse' Mentor
Pros: > Vast stage with pinpoint layering and imaging: the very definition of a 'holographic' IEM
> Wonderful tuning across the FR, with excellent balance and an overall sense of warmth
> BA bass, as good as I expect is possible without a DD (BCD effect)
> Lush, enveloping mids
> Crisp, airy, highly engaging treble with a perfect amount of 'bite'
> Mid-sized shells are comfortable for long listening sessions, zero pressure build
> Everything you could need in terms of accessories
> High-quality stock cable from PW Audio
Cons: > Shells don't feel quite like a premium look/finish
> Very Occassional spicy upper mids (this might be me...)
> BA bass (subjective, but some might want that indistinguishable DD experience)
> Not cheap...
"The multiverse is a hypothetical group of multiple universes. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them" Wikipedia

Unique Melody Multiverse Mentor - 12 BA, 1 Bone Conduction Hybrid IEM ($4,499)


Introduction & Caveats

The Multiverse Mentor (MM) is the third set I've now owned from Unique Melody (UM), the previous two no longer with me - first was the infamous MEST MKII which I purchased around it's launch in 2021, and then the MEXT early in 2022, in fact, I think it was my first purchase this year. I enjoyed both of these sets but ultimately moved on as part of the usual cycle of upgrades and exploration. I've been intrigued by various UM releases over the last year or so, quite a few such as the Indigo get a lot of incredibly high praise in the community, and I've been keen to try something that is considered at the level of Traillii or Jewel - which is exactly where MM is positioned. The Mentor arrived on the scene only a couple of months ago, and early impressions from the few trail-blazers that jumped in early were I would say unanimously excellent, a rare feat in this community. I had only recently parted with both Traillii and Jewel, and sort of 'settled' with Kr5 as my only multi-driver set, otherwise having a preference for mostly the humble single DD as a collection focus... alas, curiousity got the better of me, the usual FOMO when hearing all of the gushing praise for Mentor from Head-Fi members who've owned the very best sets on the planet - how could I resist?!

As always, I like to note that I am not a professional reviewer - this is my hobby, and I enjoy trying out various sets and sharing my thoughts. I often get a discount in exchange, but it in no way influences the content of my review - I choose the sets I am keen to try, and this typically means I've done a fair bit of research before pulling the trigger, getting a good sense as to whether it will be a set I will likely enjoy - and for the most part, this has been the case... hence my positive ratings. Some last longer than others, there are only so many I can afford or have the time to hold on to, and part of the enjoyment for me is testing various sets and determining how they compare to my existing collection.

I would like to thank @MusicTeck as always for the opportunity and their industry-leading customer service. Always an absolute pleasure to deal with, and arguably the best audio dealer in the universe... or eh, multiverse.

The UM MM retails for $4,499 and is available from MusicTeck HERE



Unboxing & Accessories

For anyone who has owned a product from Unique Melody already, the overall unboxing experience will be quite familiar, albeit steps up somewhat for this higher-end of the market versus MEST MKII for example, but not a million miles away by any means. I like the UM unboxing, it has a lovely premium feel to it, with a jewellery-like presentation - this has moved up a notch now also with the addition of a soft fabric bag covering the case inside the box, very reminiscent of how some watches are unveiled.

Outer Box: (there is actually a silver outer-outer box, but I decided to omit from these pictures as it's more a protective box)


Under the hood: The aforementioned cloth bag that holds the case... certainly gets the dopamine juices flowing, or maybe that's just me...


The MM in all it's glory, revealed inside it's carry case:


Some words of wisdom from Mr Einstein to ponder before sliding out the tray of accessories:


Contents of the tray, everything you could possibly need to get going with Mentor... (note the few raindrops on the table, my photo-shoot had to then move indoors!)


Accessories laid bare...


The supplied custom stock cable, made by the highly-regarded PW Audio is a 4-count, 26AWG copper and silver-plated cable. This is a shielded cable, with a fabric finish. It looks and feels incredibly premium, and I suspect would be relatively expensive if sold separately. I'm not 100% sure whether there are options on the cable termination, my came by default with 4.4mm and I can't see an option to choose another on the Musicteck product page. It's pretty thick, quite heavy, and does have some microphonics, as such not ideal for moving about the place, or certainly not going for a jog or walk - I don't expect many will have that in-mind anyway for a set at this sort of price point... personally, the ergonomics of the cable in this case are not an issue, as I'm typically seated when enjoying MM, or indeed any sets at this sort of level. I appreciate that many have their favourite cables anyway, and might skip the stock altogether - it must be noted though that this is a premium cable, and significantly better than some competitors at this level.



The faux-leather case is made by a 'well-known' South Korean manufacturer, probably no prizes for guessing but I'll stop short of listing anything here, as I don't know for sure. It is indeed a high-quality case however, and is certainly of a size to comfortably hold MM and the relatively thick PW cable.



The supplied tips will again be familiar to anyone who has owned another product from UM, the stock silicone and 3rd party 'Xelastec' from SednaEarfit seem to be the standard with any UM product, and should certainly provide an option for most ears out of the box, in the very unlikely event you don't have a selection of others to choose from.


Design & Fit


According to UM, the shells are made from aviation-grade carbon fibre - they are smooth to the touch, reasonably small, and presumably quite robust due to the materials used. The shells are nice, and they do feel well built - a nitpick, but I do feel they could up their game somewhat in terms of the overall finish, they don't quite hit the mark for me as a $4.5K IEM.

They are terminated with a slightly recessed 2-pin connection, and the stock cable feels very secure. There is a small vent to ensure no pressure build, something I am very prone to and thankfully have had no issues to report here, and an absolute deal-breaker now if any set causes even a small amount of pressure.

From a fit perspective, they sit very comfortably in my ears. I've been using the SednaEarfit Azla Short Standard variety as opposed to any of the included tips. I struggle with shells that are even somewhat large, and I was nervous than Mentor might be an issue - thankfully not the case, but I think even slightly bigger and they may have been a problem. I've had many extended listening sessions (>two hours), and have had zero fatigue.


Listening Impressions

I've been listening to Mentor on a few different sources, and I'm finding great synergy with all of them - my favourite however is probably the latest addition to the collection, the excellent H7 from Shanling which just arrived with me a few days ago. The H7 strikes an excellent balance in terms of a clear, somewhat neutral sounding source that still drives huge power into the lows. Aside from the H7, I've had many hours on both the LPGT and Shanling M9, both offering a different perspective on the same set, with M9 as one might expect driving more emphasis to the lows, while LPGT of a more neutral variety.


MM are the single most impressive set I have had the pleasure of trying on my IEM journey to date: exquisitely balanced across the frequency range; wonderful deep lows, lush/engaging mids, and super crisp treble, all wrapped up in a set that has what I would consider to be a unique blend of technical mastery and summit-level engagement factor; a tricky feat to achieve. They comfortably tick that 'all-rounder' box for me, in that they often knock the ball out of the park with ease for absolutely any genre I've tested... however, they are of course better with some genres than others - personally, I would be more inclined to load up various sub-genres of electronic music with MM, and less inclined to choose something such as modern classical - the reason being, I do prefer dynamic drivers from a timbre perspective when it comes to instruments such as piano or strings, both of which often feature in modern classical music. But again, I must note this is quite marginal: I will happily listen to modern classical on Mentor, and thoroughly enjoy - just my preference when owning multiple sets would be to grab something like the Turii Ti in those scenarios.


I hate to use the 'for a BA' descriptor, but I feel it's appropriate - so here it goes: Mentor has the best bass 'for a BA' that I've heard. Mid bass has excellent impact and feels incredibly defined, I honestly would be hard pressed to distinguish at times from a dynamic driver if tested in a blindfolded listening scenario - genres such as techno, house, IDM to name a few of my favourites in electronic often call for solid mid bass delivery and I've been constantly amazed when firing up these portions of my library: there is often even almost a sense of air or vibration that one would expect from a DD, presumably this is due to the bone conduction, which certainly delivers. There is a bit of a bias towards mid bass over sub, but those lower registers still certainly convey a wonderfully visceral experience when called for, and I think again overall, it strikes an excellent or maybe even perfect balance - I don't get a sense of mid bass overpowering sub, or vice versa - they are wonderfully distinct and respectful to one another, and indeed form a solid foundation for the unique soundstage, which I'll come to later.

A critical element to an emotive & engaging listening experience are how the mids are rendered - In my experience, I would say a few key components must be achieved: smooth, clear, unimpeded with good body, realism, and a touch of warmth - MM as one might expect at this level, ticks all of these boxes, and probably many more that I've not listed here. Vocals and instruments are beautifully rendered, and really do enrapture with a unique sense of delivery, again this seems to be that secret sauce of bone conduction magic... it provides a core foundation to the entire listening experience, that really is like no other. Again, this should go without saying at this level but I'll note none-the-less; there is zero congestion, the most complex of passages in an absolutely any track I've listened to, always have ample space and speed for each component, more often than not actually amazing me as to how the heck an IEM can position from an imaging perspective with such a vast sense of location on stage. There can be a touch of spice in the upper mids in some very rare scenarios, so rare I can't even pinpoint where it has happened and it might be a sensitivity in that area I've flagged in the past.

As I learn more about how IEMs perform, and indeed what my own preferences are, I've got a better handle on the crucial role treble plays in a finely tuned set: too little can result in a set that steps back from a technical perspective, especially in micro details - and indeed the higher registers of instruments or vocals can fail to reach the soaring heights they might otherwise... too much, and there is a risk of the dreaded sibilant vocals, or harsh/piercing tones that scream all the way into the depths of your skull. A good balance is often just on the cusp of being too much, and I guess this is easier to achieve when you've numerous drivers delivering the goods, as is the case here with Mentor, and needless to say UM have certainly tuned just below this tipping point. There is ample zing at the upper end to provide a good crisp delivery of hi-hats and allow instruments soar to the upper extremities, but stop short of any discomfort.

There is a unique soundstage with BCD the foundation that seems to allow sound to emanate outwards from a central point in my head, to what feels almost infinite distances - of course it ends, but I find a sense of vastness that is almost hard to pinpoint, I guess this is where UM were coming from in the context of ‘Multiverse’, it feels like a well chosen name. While it’s not especially airy, it has more of a binding warmth that still allows what I consider industry-leading imaging and layering in a very distinctive and cohesive atmosphere - it has the charm of Traillii, with near enough the technical prowess of Jewel, and for my ears at least, beats both in terms of the overall package. Detail retrieval from the absolute smallest, to the biggest and boldest, is there in abundance but again, delivered in a cohesive presentation.



Vector Lovers - Melodies & Memory (IDM / Downtempo / Electro)

This track features on the excellent 'Capsule for One' reissue, originally released in 2005 on the legendary Soma label. This falls under the downtempo / IDM / electro umbrella, and for me, is about as good as it gets when played on Mentor. I mentioned above how the bass is wonderfully balanced between sub and mid, and this is absolutely evident in this track - the mid bass kicks with massive authority, and the sub rolls adjacently, in touching distance but comfortably apart. The synths are beautifully rendered, and seem to soar across the stage as they emerge and fade away - the vocals sit centre stage, and for my ears, in a perfect position that doesn't push too far forward or back.

Jane Weaver - Heartflow (Psychedelic rock, female vocals)

This is a great example of a track made with 'real' instruments, and I don't have any issue with timbre - it's a busy, lively, energetic track and Mentor as you would expect, has absolutely no issues with numerous instruments and vocals charging to the fore - in spite of the complexity, it's very easy to still pinpoint individual instruments and at the same time, enjoy the full performance. Jane's vocals are again as above, in a perfect sweet spot for me where they are in line with the music; not forward or back and quite central. Vocals certainly a huge strong point with Mentor, I'm not sure whether the BCD can take any credit here, but I expect it's playing a role along with the BAs for the mids. I've noted previously how I prefer Turii Ti for some instruments, but it does tend to be within the more relaxed genres where there is more of a specific focus on an individual instrument, this is not the case for this track, and indeed many others like it.

Ceephax - Telephax (IDM, Acid, Ambient, Techno)

A recent purchase, and likely a late entry to my favourite albums of 2022. Ceephax records also as Ceephax Acid Crew, which is a nod towards late 80s / early 90s acid house - I've never been to his gigs, but they certainly look fantastic from what I've seen on YouTube. His recordings as Ceephax are more towards the subdued, melodic side of electro/techno, and this latest album is certainly a fantastic example. It's again a genre that really excels on Mentor, I find a genre like this is best presented when bass, through mids and treble are well represented, and you can get that sense of deep bass, lush mids, and crisp treble to truly appreciate the full production. There is often quite a lot of intimate details in these tracks, that can be lost in some sets - every single detail of 'Telephax' is presented in it's full glory, and is a wonderfully encapsulating experience. While listening to type up my thoughts, I just wanted to hit repeat and go again, a fantastic track from an extraordinary album.

Akuratyde - Evergreen (Electronic / D&B)

I always, without exception test D&B on an IEM - it's a great genre to test how a set handles the complex drum programming, that can easily become harsh or congested due to the frequent snare and hi-hat hits - not to mention the need to ensure it can dig deep enough to render the sub bass well, a signature of the genre, as the name 'drum and bass' suggests. No surprises here, Mentor scores top marks for this excellent track - a big and bold presentation, with complex percussion handled with absolute ease. The melodic synths seem to float about in unison with the drum programming, and it is again an incredibly captivating experience. I will certainly file D&B under the Mentor banner for future listening.

T.R. Jordan - Encoder Error (Electronic / Ambient)

This is not only one of my favourite albums from 2022, but already what I would consider an ambient classic. I have played countless times since I purchased early this year, and it's often an album I choose when I can't sleep, something that happens all too often these days. Anyway, I know the album intimately well, and am reasonably fussy about how I hear it. Mentor does a very good job, but I would say falls a little short of excellence - this is where Turii Ti steps in for me, I prefer the more 'gentle' tuning, the airy presentation, which for me is more natural and organic sounding for this genre. Don't get me wrong, I could absolutely happily enjoy/love/adore this album on Mentor, but I'd be less likely to reach for this set for this music while Turii Ti is in reach.

Symbolico - Gaian Portal

This is a work of production genius, and an ideal track to test the technical capabilities of a set - and indeed to experience an utterly visceral experience when the right drivers are plugged into your ears. Again, we are back in a territory here where Mentor shines, an absolutely perfect set to capture all of the intricate details that spread out across the huge stage, new sounds presenting themselves, while others fade out into the distance, climatic moments that likely have every single driver in Mentor firing on all cylinders, and proving the technical prowess of tuning achieved here. It's honestly a fascinating, and highly engaging experience to hear this track on a well tuned IEM, and Mentor is as good as it gets in my experience.


Oriolus Traillii
While I no longer own, I am going to attempt a brief high-level comparison with the legendary Traillii from Oriolus. I adored Traillii, however that comes with two key caveats: the first being pressure build, and the second being the need for 'focus time' for me to properly enjoy, something I often noted when sharing impressions when I owned the bird. Traillii was a more gentle listen, I think more of a relaxed and smooth finesse to the tuning - it was because of this, I always had to focus my attention to really appreciate the tuning. Traillii has a bit more extension in the sub bass, while steps back in mid bass - Mentor certainly packs much more of a punch here, there was no mistaking the fact that Traillii is 'only' a BA driving the bass. Overall, Mentor is certainly a more energetic set. If it wasn't for the pressure issue that presented itself from time to time, I probably would have held on to Traillii for those magic moments of focused listening, it's certainly a complementary set to Mentor for those that can own both.


Softears Turii Ti
Mentor is in general much more impactful in it's tuning; the notes are larger across a much larger space, as such it grabs your attention in a more macro way - quantity of low-end is significantly enhanced, and lends itself above Turii Ti in general to more energetic genres - Turii has a more graceful tuning, an airiness that is somewhat gentle and in my experience, instruments such as strings or piano sound more authentic and ethereal. While Mentor can comfortably play strings, and do so very well, I would certainly choose Turii Ti for this type of music as I feel the weight and density of notes are excessive in comparion when I play on Mentor, Turii Ti is more visceral for genres that focus on strings, vocals, acoustic etc. Either set can play any genre, and Mentor on the whole a stronger all-rounder, but Turii Ti has it's superpowers in my opinion from a timbre perspective with specific instruments or genres. Taking a genre like Modern Classical, Mentor will 'wow' you with the vast stage, and stunning imaging and layering - Turii Ti steps back in that regard, but for me at least, wins the timbre prize, and becomes a lot more emotionally engaging as a result.



The Unique Melody 'Multiverse' Mentor is without question the most impressive, and I would say 'best' IEM I've heard - it comfortably surpasses both Jewel and Traillii by quite a margin, combining a superb blend of sheer listening engagement, and world-class technical mastery. It's hard to label an IEM as 'perfect', because that is quite a statement, but I feel inclined to say it's certainly incredibly close in terms of at least some of my listening preferences - maybe a DD for bass, maybe some timbre improvements, and maybe remove those brief upper mid challenges that pop up on a rare occassion, that might just allow me to say Mentor is perfect - but on the flip side, these changes will have a knock-on affect, and Mentor would no longer be what Mentor is today - an exceptional set, that delivers on a vast amount of fronts, and absolutely earns a seat at the table of the best IEMs on the planet, or indeed the multiverse...



  • IMG_0754.jpg
    1.6 MB · Views: 0
Last edited:

About the bass, competitive with the fir Kr5 ? 😉

And nice review 😎👍
Scuba Devils
Scuba Devils
@DaveStarWalker - it’s reasonably competitive, but KR5 takes the prize for me due to the dynamic driver. KR5 remains my top choice for a hybrid IEM at the moment, fantastic IEM.
Ok thanks. Very interesting bro.


1000+ Head-Fier
Unique Melody Multiverse Mentor Review
Pros: - Beautiful vocals and strings
- Bone Conductor Effect
- Good quality cable bundled
- Great fit (for me!)
Cons: - Various face plate finishes in the wild
- Cost



Unique Melody gave me my first introduction to bone conductor drivers in the Mest Mki. It added a little bit of magic to that set and was something I immediately connected with. Since then I have always had at least one set in my collection that has a BCD. While I’ve kept clear of the ultra-expensive models UM has released over the last while, very positive initial impressions from the community were enough to draw me back in and pick up Unique Melody’s latest set from Andrew in MusicTeck.

The Unique Melody Multiverse Mentor, to give it its full name, is a 12 BA & 1 BCD set. There are 4 BA looking after bass, 2 for Mids, 2 for Mid Treble and 2 for Treble along with the piezoelectric “frequency shift” bone conductor driver.

The shells are made from carbon fibre with ceramic frames and a “Banksia Seed” face plate. The IEMs have a recessed 2-pin socket and come with a high-quality cable from PW Audio with a similarly interesting name, “Deep of Universe”.

The shells are a standard hybrid shape and size. I have had no fit issues at all with them. I have been using SpinFit W1 tips with them and once inserted, they stay put and I never need to readjust them.

As you will see from the images I took, there seems to be a range of different face plate colours out there. The unit I have is quite dark compared to the product shots but I have seen others that are somewhere in between.

I’ve been listening to the Multiverse Mentor for the last few weeks and these are my resulting impressions. I am only one voice so please treat these impressions as such and remember that we all hear differently!

What’s in the Box​


The packaging Mentor comes in is good quality and an improvement over my previous experiences with UM. The cardboard is good quality and the tiered box is well put together.


The Dignis vegan leather carry case is presented in a white dust cover which you would usually associate with high-end jewellery or handbags so you get an idea of what UM are aiming for.


The carry case is very soft to touch and feels good in the hand. I am not sure how the softer material would stand up to rough and tumble of commuting in a laptop bag, but it is certainly a nice case to keep the IEMs in on your desk.


UM includes two different types of tips in a number of sizes along with a warranty card and a cable clamp.


Mentor has a fairly natural tuning which is very easy to listen to. Bass is elevated and is assisted by the magic the BCD adds.

I often find it hard to describe the effect a bone conductor has on the overall sound of an IEM. Graphs just don’t tell the full story and that is definitely the case here with Mentor. The vibrations from the BCD give a tactile feeling to drum strikes and strings being plucked while the Mids have a body and presence to them that you just don’t find in sets without this type of driver. The combination of details, clarity and that presence that the BCD brings add up to a very interesting listening experience.

That BCD also helps to create a 3D soundstage with excellent imaging, layering and separation. The size of that stage varies with source but the sense of having music coming from all angles or spaces around you is present even with weaker sources. The ability of the set to build a picture in your head of where each instrument is located within the stage is impressive and combined with the level of detail, it adds to that sense of “being there” rather than just listening to a recording. I really feel the BCD has a big impact on the overall listening experience. It takes good tuning and adds an extra level of engagement, and for me, it is why Mentor stands out from many other sets.


There is a certain familiarity and nostalgia attached to dynamic drivers. Most of us grew up listening to speakers which had dynamic drivers and when it comes to bass the air movement generated by these types of drivers has a very distinguishable effect. For some, BA drivers will never be able to recreate bass how they want but the introduction of bone conductor drivers I would suggest has changed that reality somewhat. If you can’t get past a set not having a dynamic driver to generate bass frequencies then there is little I am going to write here that will change your mind but I would suggest you open it and explore what sets like Mentor can now offer.

We all have test tracks we like to play to test the different aspects of bass. For me, many of these tracks have drum solos or detailed isolated drum strikes that allow you to follow from initial contact with the drum skin right to the end of the decay. If I play one of these tracks back to back on Mentor and on a dynamic driver set then it’s easy to pick out how the dynamic driver sounds more true to life and how the texture and decay just sounds more familiar.

During all my casual listening with Mentor though, it has been incredibly rare that I have even noticed what type of driver is generating the bass. You don’t notice unless you go looking for specifics that you know the BA drivers can’t produce when compared to a dynamic driver. Sure, you don’t get the same sense of air movement, but you do get impact that isn’t lacking, along with the vibrations the BCD is creating and as an overall package, the bass quality is excellent.

While the BA characteristic of speed is there, the timbre is a hybrid due to the BCD effect and something you have to experience to fully understand. There is a sense of rumble far beyond what I have experienced in any other BA-only set.

The simple fact here is that Mentor creates a better bass experience with the drivers it has than many lesser dynamic driver sets and I think for a lot of people this set will change their preconceptions about BA bass.


Note weight, details, and clarity. All stand-out aspects of the mid-range of Mentor. Mids sound beautifully natural and accurate but there is a combination of details and body to them that is unique.

Vocals and stringed instruments are exceptional. There is a fine balance between warmth and detail with neither ever allowing the other to ever take over. Sometimes sets that have so much detail and resolution on offer can lean cold or lack a little emotion but Mentor balances it beautifully. Vocals are life like, crystal clear and importantly for me, connect with you.

There were times during my testing when I came across tracks which I found to be a little too energetic for my tastes in the upper mids but after extensive tip, cable and source rolling that has come down to the stock cable for me, but this, of course, is all down to personal tastes and not an issue with the set itself. With the stock cable there can be a little more bite or crispness in the upper mids compared with other cable combinations, which I will go into further below.

I listen to quite a lot of acoustic music which has just a couple of instruments and a singer and for genres such as this, where the mid-range is so important, Mentor is fantastic. It allows you hear and appreciate every detail but there is more to the overall experience than just hearing details and I think this is where the BCD really elevates things. The sense of feeling it adds along with a soundstage that gives that sense of being at the venue or in the recording studio with the artist, creates a listening experience that is unique.


The BA treble of Mentor is clear, detailed and extends well. It is easy to listen to and has never become fatiguing. It doesn’t have the great sense of air or shimmer that piezo or EST drivers can create but it also has non of the problems that often accompany those drivers. The Treble is in line with the overall tuning and is capable of handling pretty much any genre. While there are no party tricks here, having well-tuned treble that can handle various types of music is very welcome and something that many sets just don’t get right. Treble is one of the last things on my priority list when assessing a set but often the first to rule a set out.

This really is BA treble done excellently. There are no spikes or harshness and everything is incredibly detailed and natural.


The Multiverse Mentor is an expensive set of IEMs. As a result, I have specifically picked tracks and equipment set ups that I know bring the best out of the set I am comparing Mentor against so hopefully people can get a an idea of whether the outlay is worth it for them or not.


Noble Kublai Khan​

Kublai Khan is an impressively technical set for its price and if it clicks with you, it can be a very rewarding set to own. It is definitely not a “one and done” type set though. It has strengths from its driver config that certain types of music really bring out.

Trøllabundin by Eivør

Listening was done with a Hifiman EF400 in Low Gain OS, which suited both sets more than NOS.

I am not sure what genre this track exactly fits into but Kublai Khan is suited to it perfectly. The track is mainly focused on the singer’s vocals, which are captivating, along with a drum beat accompanying her throughout. With the right gear, the track has a sense of grandeur, like you are listening to the singer perform in a huge open space. Bone conductors really help to amplify this and I have often felt this track sounded quite flat when I listened to it on sets without them.

With Kublai Khan, the drum beat in the opening seconds like it is in the room with you but your attention is then quickly drawn to the singer’s voice and rarely leaves it after that. The vocals are smooth and almost have an ethereal feeling to them from the piezo tweeter when the singer hits the higher notes.

As the track opens up, the sound stage becomes huge but your focus remains on the singer’s voice.

Swapping to Mentor, the first thing I looked for was how the opening drum beat compared. For sure, with Mentor there is less intensity to each strike. You lose some of that feeling of each strike that DD texture brings to the table. What you don’t lose though is quality. Everything sounds exactly like it should.

Where the differences in these sets really shows is the body and weight of the vocals. With Mentor, the vocals are more detailed, grander, and carry more weight but yet come across as smoother than with Kublai Khan which when compared back to back with Mentor has some sharp edges.

For this track, the drums definitely go to Kublai Khan but for where it counts in vocals Mentor produces a more enthralling experience.

Stupid Girl by Garbage


This is one of my favourite tracks to listen to with Kublai Khan. It does an excellent job of clearly separating all the different instruments and the vocals so it’s easy to hear them all. Nothing is overpowered and as the track gets busier you don’t feel overwhelmed or like many sounds are blending into one, which happens with many lesser sets. Vocals and instruments are all positioned equally and it is a very enjoyable listen.

Swapping to Mentor, there’s some noticeable differences in dynamic range and note weight. The bass line is more prominent, as are the drum strikes. The different sounds and effects that come into the track are positioned in a more 3D space and their intensity grabs your attention. There’s noticeably more details and clarity in the vocals but at the same volume levels as Kublai Khan, it is a more intense listen.

When I swap back to Kublai Khan again, the difference in details is immediately noticeable but it is a smoother listen so it will be a toss up between which you value more to pick a winner between them on this track. Personally, I would lean towards Kublai Khan.

Interestingly between the two sets, it is not BA vs DD bass that dominates the comparisons. Both do bass very well and are helped out with BCD drivers. In all my listening comparing them, the differences in treble was something I spent a lot more time comparing to decide which I preferred. With all that said though, the superior mid-range and details on offer from Mentor stand out.


Softears Turii Ti​

This was an interesting battle for me. A politely tuned singe dynamic driver versus an all BA set with the big question being what does the BCD in Mentor bring to the table.

Take the Power Back by Rage Against the Machine.

Cayin N8ii Tubes/P+/AB/Low Gain


Like most tracks on this album, Take the Power Back is aggressive and hard-hitting. It’s a busy track and what I am mainly looking out for is how easy it is to clearly hear each instrument, the vocals and if it’s a coherent listen amongst so much intensity.

With Turii Ti, the intro sounds excellent. The drums and bass guitar are accurate and sound great. As the vocals come in they are clear and easy to distinguish. As the electric guitars enters in stereo, it completes a soundstage that wraps in shape from one ear to the other. There is nice positioning and separation but the soundstage isn’t huge and as the track intensifies, that leaves a lot of sound focused in what feels like a small area. Turii Ti handles it well though and once you keep the volume at reasonable levels the whole track is presented well.

Swapping to Mentor, I initially thought the first stand-out difference would be the bass drums strikes in the intro followed by the opening bass guitar line but that wasn’t the case. Turii Ti probably sounds a little more life-like in its reproduction of these two instruments but Mentor has more impact and weight to the notes and you would be forgiven for thinking this was the DD set.

The soundstage stretches slightly further left and right with Mentor but the depth is about the same.

There are two clear differences between Mentor and Turii Ti here though. First is the difference in detail. With Mentor, all of the instruments sound fuller and each note is more detailed and more clearly defined in its space. It leads to a more intense listen but the details are there to support that and even the more delicate cymbal hits in the background are clearly identifiable. The other difference is that vocals are slightly more forward and as there is more detail it makes them easier to hear.

Turii Ti has a slight edge for accuracy which is more evident in the intro when you can just hear the bass drum followed by the bass guitar but as the track gets busier, it is the superior details of Mentor that stand out again.

Seven Nation Army by the White Stripes

Mentor: Cayin N8ii Tubes/P+/AB/Low Gain

Turii Ti: Cayin N8ii SS/P+/AB/Mid Gain


Interestingly for this track, I had to use different settings on the N8ii to achieve a sound from both that I could compare. Maintaining the same settings as the previous track left Turii Ti sounding a little too smooth and rounded for a track that needs a little grit.

So, to a track that probably has one of the most recognisable drum and bass riffs of any song.

Listening first on Mentor, it is clear what effect the BCD is having from the off. The opening bass line has grit and vibration to it. Vibration that you feel in your head and in the seat of your pants. There’s a satisfying thud from the bass drum and the vocals are superb. Detailed, clear and never overpowered by the instruments.

Like with the previous track, the technical aspects are excellent. Everything has its own clearly defined space within the soundstage and everything is detailed and textured.

Swapping to Turii Ti, even with the more aggressive settings on N8ii, the opening bass line is still smoother than Mentor and while there is the sense of feeling the vibrations it is not as intense. Concentrating on the bass drum strikes, Turii Ti is more true to life. There is a realistic texture to the bass drum hits that sound a little 2D in comparison on Mentor but there isn’t as much impact with Turii Ti.

Ultimately it comes down to a choice between the slightly more accurate Turii Ti or the more detailed and more intense presentation of Mentor. I can happily listen to the track on both sets but I would lean towards preferring the track with Mentor as it has a little more bite which suits the track.



The cable Mentor comes with reassembles a non-shielded First Times but it feels slightly lighter and I much prefer the hardware. According to the MusicTeck website, the cable has 4 independently insulated cores which are a copper and silver-plated copper mix. Overall I have been quite happy with the cable. It’s detailed and very accurate but as I mentioned above there were a few occasions when I thought there was a little too much upper-mid energy in some tracks. Whether that is an issue for you will be down to your own preferences and no doubt hearing.


Liquid Links Venom​

Listening to Come Together by The Beatles, the differences are minimal between these two cables. There is slightly more air with Venom but with the original cable there are more details.

Bass is slightly more boomy with Venom but the increased sense of air gives notes further to travel so it does sound a little more closed in when you swap back. There’s no clear reason to see Venom as being an upgrade here vs the stock cable.


Khanyayo 4W Cardas Clear Cable​

This was a much harder one to call at first and it took a lot of listening rather than going back and forth between cables to appreciate. One first listen with the Khanyayo my reaction was “wow”. The dimensions of the stage were pushed out and it wrapped further around your head. There is a little more clarity and warmth to the vocals which I really liked but they are also somewhat darker. This is noticeable when swapping back and forth with the stock cable but not something you notice after some brain burn-in.

Bass impact increases, becomes a little slower but it can also be a little loose sometimes. It doesn’t sound as pristine or pinpoint as with the stock cable but the sounds appearing out of a black space in a larger stage grab your attention.

The pros of the cardas clear copper cable are a richer, warmer mid-range, more bass and a bigger BCD effect but this comes at the cost of accuracy and at times looser bass.

I look forward to trying different cables with Mentor as it is the type of set that you should be able to really fine-tune to your exact preferences with a little experimentation.


It has been a really enjoyable journey with Mentor so far. Getting used to what it can offer, matching it with different sources and cables and importantly finding a new way to enjoy my library has kept me excited and wanting to come back for more. Always a sign of a great set.

Note weight, details, clarity and a BCD that adds to the experience on so many levels combined with an ability to cover just about any genre makes the Unique Melody Multiverse Mentor an easy recommendation for anyone to try. It is excellent technically but also an engaging set that sucks you in and keeps you listening to “just one more track”!
Great review bro!
Great review! Looks like you got a good looking set of face plates!
Great review 😎👍