Mangird XENNS UP

Overview:

Up for review today are the Mangird XENNS Up (yeah, I’m not going to capitalize that every time – get over it). These beautiful IEMs come with a 10mm DD for the BASS, 4 BAs for the mids and highs, and 2 ESTs for the ultra-highs. They also have hand-painted shells which is a pretty cool touch. I got these as part of a trade from another Head-Fier, so I don’t have any links to share, but you can buy them from Linsoul for $700 if you feel like buying a set. On with the review!

Accessories/Earpads/Eartips (10/10):

Super nice. That’s the best way to describe the packaging on the Xenns Up. The box sleeve has the gorgeous art you’ll find on the shells all over it, which looks like flowing lava. The inner box is really nice and protective and it includes a splitter, a leather carrying case, and adapters for the cable to work with just about everything you could imagine. It also comes with several different “cards” worth of ear tips – foamies, silicon-ies…foam/silicone hybrids…you get the idea. It’s a better presentation than the $600 Meteor, the $1000 FiR VxV, and the $$1,100 Fibae 5. Heck, it’s a better presentation than much more expensive IEMs – looking at you FiR Frontier series. It earns a 10/10 here, and yes I’ll be using my Spinfit W1 tips since they're the best I've found (You can buy them here if you want a set: https://amzn.to/3WDrNIk.)



Cable (8/10):

The Xenns Up comes with a decent cable. It’s a little thick and heavy for my tastes with some annoying memory retention, but it’s a better cable than comes with a LOT of more expensive IEMs (looking at you again Fir Xe6). It also has modular ends, which I can fully appreciate, though at this level if you’re not using a 4.4mm balanced jack on your DAP/amp, that’s a bit weird. So really, at this price, it would have probably been a better idea to just include a 4.4mm attached. Still, I appreciate the options, even if some will argue that this choice will decrease the sound quality and blah blah blah – those guys already own an aftermarket cable worth more than these IEMs - they can go use that and quit complaining. It’s not as nice as the FiR Rn6 cable, but it still beats a LOT of stock cables – 8/10 points here.

Build Quality/Comfort (10/10):

The build quality on the Xenns Up is fantastic. The Xenns have great build quality and comfort with a really nice hand-painted art pattern that’s unique to each set. On top of that is a clear coating that makes them appear seamless and they have vents to avoid pressure build-up. The IEMs design sets them comfortably in your ear with curved stems and the overall housing is pretty small compared to something like the Ronin/Mentor/Elysium. They will protrude a bit though, if that annoys you, as they are thicker than some. I have no reason to take off any points here, there are wonderfully designed and built – 10/10 points.



Sound:

Check out the wolfhawk.squig.link below. I’ve thrown quite a few IEMs on here since when I originally wrote this review, the Xenns Up wasn’t available in the U.S., and the price for it roughly translated to around $1,100. At the $700 price from Linsoul, it plays in a much more reasonable playground and there’s far less competition. At the price of the Fibae 5, the Xenns Up has no ability to contest it, but for $400 less, it gives the F5 a run for its money in value. Obviously, it has less sub-bass/mid-bass than the Meteor (closest competition) and the F5, but it’s still considered a bassier IEM. The mids of all 4 are very close and the highs are all over the place, so check out the individual song tests below for a clearer picture on what all of that means.



I am powering these from my HiBy RS8 with the A/B amp on medium gain at around ~40/100 volume. I’m using Tidal Hi-Fi with MQA enabled and the 4.4mm jack with the stock cable.

Lows (15/20):

I’m starting off with the Mid-bass/Sub-bass test I’m using David Guetta’s “I’m Good (Blue).” There is really good, full-bodied mid-bass on the Xenns Up, with just a tad bit of unwanted distortion. There is also good sub-bass, though the wind-up is hard to hear. These are quite bassy, and probably one of the best bass presentations in this price range. It’s not Fibae 5 levels, but it is very pronounced overall – and drowns out the mids a bit. For the bass quantity/quality test though, these get near full points with a 9/10.

Up next is Demon Hunter’s “I Am A Stone,” which I use to test whether the bass is too strong and overwhelms the mids as that is just as important as how strong/good the bass is. The Xenns Up is not really a mids-focused IEM, as evidenced by this song. The bass is the star of the show here, and it does occasionally overwhelm the mids. It’s better than some bassy IEMs, but still very pronounced. 6/10 points here.

Mids (9/20):

Weaving The Fate’s “The Fall” is my test song for clean/dirty guitars and vocals with background instruments to see how clearly the vocals/guitars can be heard. The intro's clean guitars are very quiet, but clean and detailed. The dirty guitars come in muddy as a wall of sounds with no real definition. The bass guitar of course comes across quite strong here. The vocals are decent, but pushed pretty far back in a soundstage that feels a bit artificial. 2/6 points.

Staind’s “Something to Remind You” has clean electric guitars and wonderful vocals – this song tests vocal quality and background noise. This song can sound really magical on some IEMs – the Xenns Up doesn’t manage to capture that magic with its recessed mids and emphasized lows. Detail is missing and the vocals just sound OK – not the worst, but not the best. 2/7.

To test classical instruments in the mids, I’m using The Piano Guys' “Code Name Vivaldi.” Woah, there’s so much low-end presence on this it’s almost overwhelming. It really brings a LOT of emotion to this song, though the pianos and mid-cello are pushed back more than I’d like. This IEM is a bit of a broken record for me – lots of bass and pushed-back mids – still, it has its charms and this song is a good example of that. 5/7 points.

Highs (13/20):

To test sibilance on headphones I use Panic! At The Disco’s “High Hopes. There is not a ton of sibilance on these IEMs, but there is still a noticeable amount. They are definitely above average on sibilance though. 4/6 points - solid.

Dream Theater’s “The Alien,” is the highs test song I use to see if the cymbals/high-hats/snare drum can be clearly heard and distinguished from the rest of the music (also good for instrument separation.) There is some highs presence here, but it’s pretty muted and nowhere near the level of something like the VxV. That said, the Xenns Up doesn’t have the sibilance the VxV has either – it’s always a trade-off. Still, you can hear a little of the cymbals in the background, so it’s nowhere near the worst I’ve heard. 3/7 points.

Michelle McLaughlin’s “Across The Burren” is another of my favorite highs/sharpness test songs as it can easily sound painful on some headphones. I’m not really expecting any sharpness here based upon the two previous songs and I am not disappointed. The Xenns Up aren’t perfect on this song – there’s the occasional cringe note, but they get close enough for me to award them 6/7 points.

Soundstage/Instrument Separation/Imaging (6/10):

I use MGMT’s “Time to Pretend” to test soundstage, instrument separation, and imaging. The Xenns Up has pretty good imaging (3/3) on this song and a decent soundstage (2/3.) The instrument separation isn’t that great though (1/3.) 6/10 points here.

Comparisons:

Update: Linsoul now has these for $700, which makes them a solid bargain under $1k – it also means they’re competing more with the Meteor which costs a couple hundred less. The below paragraph was written before Linsoul had them and they were harder to find, but it still applies so I’ll leave it in the review. I personally like both the Xenns Up and the Meteor, so just grab the one you want to pay for – the Xenns Up feels a little more premium than the Meteor, but I prefer the Meteor’s sound – you may not (some people like it, other don’t).

The Xenns Up runs around $1,100 if you can find a pair. That puts them in direct competition with the Fibae 5 and FiR VxV. To be blunt, I’ll take the Fibae 5 over these any day of the week if I’m looking for a bassy IEM – though the Fibae 5 will likely cost quite a bit more used. If I’m looking for an IEM with great Mids and Highs, but low bass quantity, the VxV would be my choice as well. The Xenns Up has really good sub-bass and avoids a lot of sibilance and sharpness, so these will likely please EDM lovers. Those in search of forward mids and great detail will need to look elsewhere and anyone looking for forwards/detailed highs should do the same.



Conclusion:

Geez, I have never had to adjust the volume knob so much on a set of IEMs. That said, these are definitely a bass-lovers IEM. They are the exact opposite of the FIR VxV and the recessed mids and highs don’t play to my preferences, but they may to yours. I’d personally still recommend the Fibae 5 over the Xenns Up if you’re looking for a bassy IEM – it’s an all-around better IEM.

TONALITY: 8.5/10
TECHNICALITIES: 9/10
CONSTRUCTION: 8/10
SOUND VALUE: 8.2/10

Intro

''Mangird was started by a small handful of young engineers passionate about music and high-resolution audio. Combining their knowledge in electrical engineering and studio performance audio gears, the Mangird team has since produced numerous professional in-ear monitors that have stirred up a global sensation. Some of these include the Xenns UP, which combined the latest driver technology with a powerful tuning, and the Tea, which was beloved for its precise balanced signature. The Mangird team is committed to hand-producing each of their units in small batches to ensure top-of-the-line quality assurance and a bespoke character. Make every song your own with Mangird.''

Personally I haven't try any Mangird products before, but read lot of good things about them. Its unclear if the company name is Xenns or Mangird, and it seem this company don't have official website. So, who know, perhaps it's one of those Linsoul sub-brand, but more official info will be welcome for a company aiming mid tier and high end audio products.
Anyway, this company seem to focus on hybrid and tribrid IEM, and there Tea 1DD+6BA get good praise.

When I know a canadian fellow have a pair of the Xenns UP, i can't hold myself to asking him a loan and thanks to Tone Deaf Monk generosity, today I will be able to review them.

Priced 700$, the Xenn Up are tribrid IEM with 1DD for low, 4BAs for mids and treble and 2EST for upper highs.

Let see in this review if the sound benefit is high enough to worth the asking price.


CONSTRUCTION


Since these are loan unit from a friend, I can't comment on packaging nor on cable which wasn't included.
Let's begin by saying those are chunky boi, but due to their organic shape and light resin plastic material, they are comfortable but not meant for deep fit.Nozzle is big too, and I suggest you using eartips with similar nozzle size to get an open sound.Construction is OK, nothing mind blowing, but i'm a fan of medical grade resin plastic shell since it's very sturdy and hard to scratch, as well, when you drop it the shock tend to be less risky for driver inside due to low vibration transmission. Back plate design is beautifull, elegant, i like it. There a side venting port too. 2pin connector aren't embeded which is a questionnable design choice for secure connection, it seem the connection will loose with time, as it does with UM Mext and 3DT.
All in all, nothing to complaint about construction.

SOUND IMPRESSIONS

The Mangird Xenn Up is all about smooth balance which can be perceive as warm L shape with extra crispness on top to smooth W shape.
Sure, the bass is boosted here and even add hint of warmth to mid range, but this permit an organic cohesion that bluff the listener thinking he don't listen to a tribrid packed with drivers, i'm mean, if you go into intense critical listening, you might be able to pick up balanced armature timbre, yet the sonion BA are known for excelling in mid range and this is no exception here, the implementation is examplary and all about delivering realist timbre that is appealing to the ears.

So these aren't exactly neutral, nor what I would call basshead even if low end is quite boosted. And yes, apart the bass part, it mostly follow Harman target but not Moondrop way at all, this isn't a Blessing2, it's lusher, bassier and more natural sounding than that. The Xenn Up aren't cold or lean sounding: note weight is there, timbre density have hint of euphonic warmth and treble is snappy with this appealing brilliance that avoid dryness.

I really love the bass presentation of these since we have both mid bass and sub bass boost, balanced way. It's round, weighty, fast and just a hint warm in definition so transition in mid range doesn't feel scooped artificialy. It's a thick and juicy bass that have plenty of slam when calling for, the rumble is vibrant with short resonance so their no unwanted veil since it mix up with low harmonic naturaly. The extension feel elastic and versatile for wide range of impact and instrument, and while the punch have authority it never dominate whole sound spectrum, keeping it's layering quite clean. Sure it's a bit colored in tone, due to timbre that is a bit dark texture wise, but low region doesn't feel detached nor out of timbral balance.
For soul track from Gallant to Muni Long to Pip Millet, the bass had this engaging slam we need while vocal are upfront, letting bass response extend in the back. As said above, the rumble do not create alot of resonance, in fact, it's a bit tamed in natural decay and resonance too, which can be perceive with toms or acoustic kick, this will tend to denfisy the presence and impact weight.
I know a bass response is versatile when it's as good for kick instrument than for cello and contrabass, and we are in this rewarding territory. I adore how cello sound with the Xenn Up, it's not sounding like a violin when it go in lower octaves, as well, their this air vibration that is felt in the instrument body, without an over emphasis of texture that could distract us from pure tone.
When it come to contrabass, Lars Danielsson bass line sound fabulous on it's album Tarantella, the extension is clean and deep, the attack grip is well perceive, the tone and timbre is natural, in fact, even more natural than cello which confirm the Xenn Up are Jazz master that permit well layered bassist, clean open mid range that don't lack weight for piano notes and very fast and precise percussions presentation.
Yes, we are in this rare case of bass quantity meet quality here and saying it's addictive is an understatement.

At first, the mid range isn't what hook the attention the most, then you get immerse in it's richness and understand how capable and full sounding it is. The sonion balanced armature are beautifully implemented here and don't suffer from artificial or thin timbre nor too high pinna gain that can create shoutiness. Perhaps they have been customize, since i feel their hint of warmth to them as if dampened. So we have smooth, clean and detailed mid range, with natural timbre, incredible layering capabilities and good amount of lower mid range to permit good note weight, as well as dense enough male and female vocal. Again, Xenn Up nail versatility in this frequency range and the technical ability become more evident with complex tracks that are busy with sound layers since it's what stand apart here: articulation of all this sound info.
An interesting track that was very problematic with all my IEMs apart Final A8000 is ''Mars&Venus'' from Paul Epworth ''Voyager'' album, the Vince Staples vocal get either mixed up in fuzzy sound layers or too bright due to upper mids lift that try to create fake clarity, but with the Xenn Up, Staples vocal is smooth, natural, non sibilant yet have it's own layer space and is tonaly right, without any mudyness and presentation is both holographic and intimate, engaging and laid back, very impressive.
My benchmark instrument for mid range is the acoustic piano and the Up don't disappoint here, we feel the note weight, the decay is clean but not the longest. We never struggle to follow piano melody even in a crowded orchestra, yet, it doesn't feel force but effortless in it's well centered presentation.
These are transparent mids with class leading layering capacity that benefit all type of music from classical, to jazz to folk, eletronic and everything in between. We can say these are safe too, and a ''Jack of all trades, master of near everything''.
Only instrument that need abrasive attack and very textured presence will perhaps feel a bit too smooth, but this is more about treble section.
If i can nitpick something it will be that vocal and instrument feel a bit lacking in presence wideness, so they aren't presented ''bigger than nature''. As well, while not thin sounding, I don't think it would be lush or thick enough for some mid centric audiophile that like their mids very colored, it's too well balanced for that.

Ok, when we see that an IEM have EST drivers, this make us have wild expectation that often lead to underwhelming result in term of vivacity of treble presence, sparkle and extension. Let say while the highs are more brilliant and snappy than the Kinera URD using similar sonion EST, it doesn't mean the Up deliver a sharp agressive W shape tonality where the upper highs will be over boosted or ultra magnify, nope, in fact, the treble is even a hint dark with the UP. While crisp and well resolve, these aren't analytical IEM, it's too smoothly balanced for that. But this doesn't mean it can't dig lot of micro details, it just mean it's not agressive sounding on top even if ultra highs are quite sharp, snappy and brilliant in edge.
You can discover the EST presence with instrumental folk music, acoustic guitar plucking, harp, clavichord or with percussions, which sound phenomenal in sharp clean presence and crazy fast attack timing and control, in fact percussions part tend to attract our attention alot and amaze us with slightly cleaner and crisper definition, they add spatial cue and sens of much needed openess in Y axis.
You will not miss a single cymbal or hit hat strike with the UP, whatever lightning pace of the tempo.
Yet, even if sparkly, decay cut short, I mean, EST are so speedy that even resonance, sustain and decay are kept to minimal, with this sharp brilliance as a result this urgent highs delivery.
So while mostly smooth, liquid, transparent and gently detailed, the treble do have this spicy upper treble that might create wow effect or less positive distraction depending of listener sensitivity to anything pass 10khz.
What the Xenn Up treble isn't: thick, crunchy and fully boosted as a whole. To the contrary it's gently boosted in presence and a bit thin and dry due to how textured is transparency, but never to the point being displeasant or too cold. It's very well resolve with excellent layering and micro details rendering, these can pick up lot of sound info yet never going over saturated or fuzzy-trebly in resonance or distortion.
And good news, they don't boost background noise of bad recording, making them very versatile for different music genre.

Soundstage isn't the highlight of the Xenn UP, but with right ear tips it sound wide open enougn, just not very deep or tall.

Imaging in the other hand is quite good, thanks to transparent layering and precise treble, we don't struggle to pin point instrument position even if separation space isn't widest.

COMPARISONS

VS KINERA URD (1 dualDD+1BA+2EST-650$)

URD is darker, more U shape in tonal balance and more open in spatiality. Sub bass is more boosted than the UP, while less punchy in mid bass, so kick drum feel less tamed in dynamic with the Up while it's sub bass doesn't dig as deep, nor warm the mids. URD mid range is smoother, darker and more open, upper mids is softed too while pinna gain is notably more loud with the UP which have a more energic and textured but hint more compressed and intimate mid range. Treble of both these IEM is handle by EST driver but the overall tonality of UP being more energic and W shape, upper treble is more boosted so it deliver more micro details as well as sparkle and snap but the the cost of a less organic and laid back tonality as well as some spatial saturation with sound info. The soundstage is notable bigger, wider and taller with the Urd, center stage being more recessed yet clean, it feel deeper too. Imaging is a bit darker and less sharp and precise in positioning with the Urd. Timbre wise, the Urd is a hint dryer-brighter, less liquid and dense than the URD, violin will sound not as boosted in texture but offer a creamy naturalness that is highly musical as well as non fatiguing, but not perfectly define as more edgy UP presentation. In term of tone and vocal, I do find the URD more appealing since it have more low harmonic that add fullness and less upper mids presence that can overly boost texture, so while male vocal feel a bit thinner and more recessed with the UP, female vocal, especially soprano in loud passage, can feel too fowards and sometime a hitn shouty.

All in all, the Kinera Urd offer a more laid back and bassy U shape tonality with more buttery and smooth mid range and more open spatiality but isn't as well resolve and feel inferior in technical performance. Bass is slower and warmer, mids are fuller but leaner and treble is darker but again smoother, the Xenn Up pack faster more textured punch, brighter more detailed mids and sharper more extended treble.

VS GSAUDIO SE12 (8BA+4EST-1000$)

SE12 is notably brighter and more treble centric, it feel a hint more balanced V shape against balanced W shape of the UP. Why? Because the mids are a bit leaner and more recessed, thinner too than the Up. Bass is all about mid bass punch, its faster and better separated, but not as round and extended than the UP, so we have this fast BA woofer boom with good enough texture but sub bass is more about resonance than well textured presence UP offer. Mids are where i feel the UP is notably fuller sounding, more bodied and wider in presence, but not as clean and open than the thinner brighter mids of the SE12. Vocal are notably more pleasing with the UP, tone is more natural and full, presence is more stretched and enveloping, so overall balance with bass and treble feel more cohesive, less boosted in upper mids and spiky in highs. Treble is the most evident different here and let say its perhaps due to the fact it use 2 more EST driver since its quite analytical and way sharper and more vivid in detailed, near overwhelming with sound info sometime, and percussions can feel a bit too agressive and underline compared to overall warmer macro-resolution of the UP. Yet, this do create intense Wow effect at first, then can induce a treble overdose, unlike the UP which doesn't distract with micro details invasion. Spatiality wise, SE12 feel more open and airy but about same widness, just deeper taller. Imaging is superior, since it's an analytical clarity we have but it's not very realist and percussions cue will be wrong, too fowards.

All in all, SE12 sound notably more technical and vividly crisp than better balanced and fuller sounding Xenn Up. Vocal, tone, timbre is more natural with Xenn Up and tonality is more versatile. SE12 talent is all about treble and boosted clarity, yet, we get fatigue fast of it's clinical musicality.

VS FINAL B3 (2BA-500$)

Ok, this is just for fun so let's say it's impossible to compete technicaly against Xenn Up tribrid with only 2 balanced armature, i'm mean it's evident but I was still surprise to prefer the B3 musicality with certain music. Let's begin by what I prefer: tone and vocal are fuller, and overall dynamic sound less distant and tamed than the UP, the cohesion feel more natural and well rounded too, even warmer. Timbre is thicker, lusher. Bass is notably less clean and controlled, more warm in impact with less clean separation than the UP, its embrace and thicken lower mid range more too, thus this thicker lusher timbre. Yet, this bass fell thicker and more vibrant, but less clean and deep and lean in extension. Their no doubt the UP is more detailed and open sounding this time, it have greater transparency in mid range and more extended and crisp treble. Dual BA show their limitation in busy bassy music especially, where the B3 tend to go way more muddy than the UP. Soundstage is both wider and deeper with the UP and imaging have both better layering and horizontal instrument separation.

All in all, Xenn Up is superior in all regard apart perhaps vocal presence and fullness since their this hint of appealing warmth in them, but the tuning is less versatile and can go plain messy with some music at high volume, unlike the UP.


CONCLUSION

The Xenn Up are the first IEMs i ever try from Mangird and let say i'm utterly surprise by how talented they are technicaly and how well balanced they are tonaly.
To deliver this kind of smooth, transparent, engaging musicality without loosing cohesion between all these different drivers is a tour de force in it's own.
Sure, sound benefit diminushing return is present, but not as much as the Kinera URD for example, which offer a more colored tonality with darker resolution.
It's easy to love the Xenn Up, but not easy to forget the cozzy immersive musicality it offer, due to the great versatility of it's tonal balance.
Unless your a die hard fan of mid range and want it thick and lush and very fowards, the Xenn Up is a safe sounding IEM that doesn't lack dynamism and will please as much bass fan than high fidelity fans.

Big thumbs UP!

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PS: These were loaner unit. I have no obligation to review them and just share my honest impressions with you because i feel like it.

You can buy those at Linsoul for 700$ here (non-aff link):https://www.linsoul.com/products/mangird-xenns-up

Things I commented on previously with the UP:
Stage is more intimate that other IEM'S I have ( GS SE12 - Killer Stage ) That being said the UP never really left me wanting more and I honestly like this mix of intimate and wide hard to put into words the UP is special.

Not only is the UP super source sensitive but highly sensitive to poor recordings, people who listen to MP3 will find the UP plays back not great recordings exactly as they are. LOW RES. The UP will sound muddy and all the good things I said above are gone.

Now let's get into it a bit deeper.

Completely Subjective Audio Review - XENNS Mangird UP

Hello all: Thanks for reading my feedback.

I share my impressions as I hear them with my ears.
As all our ears are different shapes & sizes so what I hear as bright or bass heavy -you might hear as dull and Vise-Versa; just something to be mindful of.

What makes my ears happy as a sound signature is slightly more aggressive U shape. I love my Bass Sub and Mid Bass love it all actually; and in large quantity. With the Bass I prefer a faster decay the faster the better as to not bleed into the mids., I am treble sensitive and prefer a darker warmer replay with good extension.

I prefer the fast speedy bass of the Beryllium Coated Driver of my Xenns Mangird UP and KiwiEars Cadenza. Of course there are exceptions in the market - as I also find the bass of the Bio Diaphragm used in the Yanyin Canon special - has some special sauce like a 8" subwoofer that feels like a 12" Has the slam and some serious sub bass! And the super cool Copper Alloy Shell IKKO Obsidian OH10 does some magic to the bass.

My music Library is widely varied from; Metallica, Great White, Cowboy Junkies, Pink Floyd, Adelle, Melisa Ethridge, Hania Rani, Vilvaldi, Fleetwood Mac, Five for Fighting, Manskin, Poncho Sanchez, Jimmy Smith, Chopin, The Crystal Method just to name a few.

That dripple being said:
And as such here is my take on the: Khan (Bought with my $)

Sources: E1DA SG3 (ES9038), Shanling UP5 (ES912), TEMPOTEC Serenade X (ES9219) Geshelli JNOG J2 with AKM4493 chip. iBasso DX160 (Cirrius Logic CS43198)
DAP/TRASPORT: From Lenovo Laptop with Amazon Unlimited ULTRA HD, iBasso DX160 ,Samsung S22 Ultra with DSD Files.
Amps: LoxjiP20 tube amp and Topping A90D
Tips Used for Best Result for me and completely subjective: Short Wide Bore are my go to and I wanted to bring forth as much vocals as possible with maximizing stage. Mission accomplished with the ML AZLA Crystal tips.
Cable after rolling I used is the Hakugei Peaceful Voice I could hear a slightly warmer ummmm; over the same cable than in a OFCC cable. That’s just me I never want to come off as a cable shill but thought I would share my experience with my journey with the UP.
Some cant hear cable differences but I can not in a way that does something magical but just sounds different from one another to me.

COMPARISIONS:
Not some detailed comparisons I can offer because I only have 3 upper end IEM'S to compare.
So I did lots of back and forth with my Resin EJ07M retuned with a 3db Sub Bass bump and the GS AUDIO SE12 full BA/EST set.

LETSHOUER Custom tuned resin EJ07M - I observed that the Bass was similar in it's speed and decay of the lows. The XENNS UP hits a bit lower with more note weight, authority and emotion. Kick drums kick ass!
The Up has a larger stage than the Ej's not as 3D though, Better depth again goes to the UP - many have commented how 3D Holographic the LETSHOUER's are and I would agree but the Up's stage sounds more enjoyable to me maybe call it more intimate but if honestly makes me enjoy it more with less fatigue. Sometimes I feel the EJ's are forcing me too much information around me instead of just letting me sit back and enjoy the music.
The EJ's male vocals seemed a bit thin and not as natural as the UP , I prefer the warmer more natural tonality of the Up.
Micro Dynamics are better on the EJ's plays with more emotion more things going on around you and sounds like a smaller venue vs the UP sounds more spacious in its depth and adds to its unique replay.
Female vocals on EJ are spot on and sometimes a tiny little bit thick on female vocals with the UP.

The GS AUDIO SE12 also using full on Sonion BA & EST is a sound stage monster its what's makes this one special.
Bass is large , super fast , too fast for me I like the slower decay and note weight of a DD. The tuning is more V shaped and has a lot more high frequency energy than the UP , making the SE12 a detail monster. I prefer the more laid back presentation of the UP.

FINAL THOUGHTS:
The UP is a freaky special IEM. I did spend a crap tonne of time source, cable and tip rolling to get me to my special mix of perfectly balance of copious bass and silky smooth vocals with enough treble to give me the sparkly.
The Sonion BA and EST Drivers are superior to Knowles for me, they bring a smoother presentation to the sound less edgy than the Knowles.
I find Sonion EST have a great extension for the high frequencies that is perfect for me laid back and still detailed.
The UP does not cheap out anywhere. A great Implementation of a Beryllium coated driver for snappy Bass without bleed, thumpy fantastic note weight but still tight love it. Sonion EST65DA01 for the Ulta-high-frequency drivers, twin Sonion custom high-frequency drivers and 2 more Sonion 2300 series for the mid-highs. So the expensive BA & EST drivers do the magic. Its just the package of DD & Sonion that makes the UP different in its tuning and playback.

Cheers The(Tone)DeafMonk