
THE PLUS:
-Well balanced full sounding V shape signature
-impactfull, fun and chunky bass
-pleasant timbre without wonky spike
-good male and female vocal presence and body
-easy to drive for a planar
-snappy, dense and crunchy treble
-versatile tuning even if bassy
-big soundstage
-good sound layering extraction-projection
-great quality 4.4mm bal cable
-among best planar right now tonaly and dynamic wise
THE MINUS:
-not the cleanest resolution
-treble extension lack sparkle and air
-bass is a hint boomy, lacking definition edge and linear rumble
-soundstage lack deepness
-average imaging
-not a technical king
-bulbous housing shape tend to pop up my ears (subjective)
TONALITY: 8.5/10
TECHNICALITIES: 8.2/10
CONSTRUCTION: 8.5/10
SOUND VALUE: 8.2/10
INTRO
LETSHUOER have been around for about 4 years now, but seem to have never really nail a mass appealing tuning balance until now with their S12 planar IEM that I will review today.
They are know to make audacious IEM, especially hybrid at the time, like the Tape and Tape Pro dual DD-EST (magnetostat) IEM that receive mitiged reviews.
Priced 150$, the S12 use a 14.8mm planar dynamic driver. I’m a bit late in the hype train, but think this review will underline if the S12 are good enough to pass test of time.
Let’s dig in!
CONSTRUCTION


The S12 construction is all metal and feel very sturdy, this is the type of IEM i’m not afraid to drop on the floor. 2pin connectors feel solid enough, but i prefer recessed 2pin to avoid cable damage. Nozzle is a bit short and big and housing a bit bulbous, which to me is a design flaw in term of secure fit since these tend to pop up my ears time to time, yet its not that disastrous, especially if you use ear tips that arent slippy. Due to lot of venting port, their sound leakage and isolation is OK, not extreme.

Letshuoer permit you to choose between single ended or 4.4mm balanced cable, which is very appreciate! The high purity silver plated cable is of very good quality, thick and sturdy with solid plug and not too tight ear hook. While I like it, it tend to brighten timbre a bit, so depending of your tone preference, using a pure copper or smoother sounding cable can be a good idea. Let say that when I pair these with Kinera URD gold plated copper and silver cable, i found the timbre lusher and more appealing.


The packaging is minimalist in presentation yet very generous in ear tips number. It include a basic carrying case and great quality balanced cable.
SOUND IMPRESSIONS

TONALITY ETC
The S12 offer a brightish balanced V to smoothed W shape signature with energic dynamic and chunky thumpy bass. While not basshead level, the bass is boosted and hit hard, with warmed definition. S12 offer a muscular musicality, favorizing physical impact over crisp analytical presence. It’s not a sharp V shape that is just about bass and treble, so i can see some people finding it W shape, yet for me a W shape need extra spike in upper treble to add air which the S12 doesn’t have.
I will not write a thesis about the bass part since the presentation is pretty simple. It’s boosted in mid bass, have more quantity than quality, yet offer a very addictive and well implemented slam to music, adding fun and dynamic weight. It’s not a flexible low end, yet, not very boomy or too resonant. It hit in a weighty ”oomph”, you know, this sound, well, it’s there and you like it when it’s there even if it’s all but a well resolve and define bass response. The boost isn’t too much, and can please bass slam induced people more than rumble seeking basshead. Even acoustic bass doesn’t sound bad, while it lack lean deep clean extension for lowest bass line to extend, it have a vibrant resonance with tight rumble that add physical slam to energic bassist. This is fun well balanced low end. Energic V, not U, not clean, not well rounded, yet striking in loud impact when needed, headbanging the reality of your music. Versatile enough at they end, both for rock, soul, r&b and other beat driven music style that doesn’t need high fidelity resolution and precise separation.
The MIDS aren’t recessed, and due to vivid dynamic are betwenn lush and bright to my ears, with an euphonic timbre that is dense yet a bit fuzzy when it come to micro details or nuance. Sens of presence is full bodied yet smoothed in definition edge. Tone and timbre of instrument sound natural, but in an analogish dark way, hum, it’s not very clean nor high in resolution and we will struggle to precisely position instrument within mid range….yet, cohesion of music isn’t affected in macro resolution. While understated, the mids are quite appealing. Both male and female vocal have good sens of openess and dense presence, full bodied and free of sibilance or timbral imbalance-thanks to damped grain of planar drivers?
Yep, a hint dark, yet not lean, the mid range offer full bodied presentation that is easy to love but will not be particularly rewarding for critical listening session. It favorise body and timbre density, so for those afraid of thin mids, S12 offer natural full bodied tone enough that permit to deliver musical male and female vocal, tough the female vocal are more upfrond and well rounded in presence as Arooj Aftab voice tell me right now, with a wide lush and breathy vocal presentation.
And there come the treble, where immediacy meet crunchyness meet snap meet unique planar texture in a suprisingly cohesive organic way. Right now, the treble is both adding crunch to electric guitar and snap to percussion of rock trio Autoryno, but the percussions snap seem all about short brilliance, so their some spice to an overall dark treble presentation. S12 will extract snappiest part of percussions, tend to enlight those with metalic vividness which will add sens of excitment as well as extra dimension to the sound. Rest of treble feel full and dense, yet tamed in micro details and will struggle to restitue full percussions section if too complex. It’s a rather safe treble wich begin to roll off around 10khz, but it’s energic too so not too safe. Attack speed is very fast and well control, yet as noted it’s short on decay and sparkle, so not an airy but not a muddy treble presentation too. This is the kind of highs that have extra body from low harmonic yet softed high pitch loudness, so resonance doesn’t open up making clavichord a bit dry but acoustic guitar sound full and have enough hint of brilliance and snap, violin too sound lively and have good attack bite this time, electric guitar is agressive enough as well perhaps underlining S12 as good for not too complex rock.
TECHNICALITIES ETC
This is the interesting part. Planar IEM technical performance is very unique and S12 seem to have favorize tonal balance and dynamic feeling over pushing technical perfection higher like the P1plus do for ex.
It result in fast attack with blurried edge but snappy fuzzy sustain (we talk about micro seconds here). I repeat the sound isn’t crystal clean, and this is surely due to subtle harmonic distortion inherent to planar driver. To some extend, in critical listening session, we can find the attack a bit shouty from low to high, due perhaps to concentrated resonance and in my case change the cable to a litz copper or gold-copper-spc did warm the dry edge of attack.
Resolution is effortless, yet not exactly what i would call crisp since instrument presentation is holographic, well shaped in body yet not sharp in presence definition. We have an euphonic analog feeling with the S12, and this is to the cost of reference grade performance.
Spatiality is very immersive, very wide tall and open with minimal deepness, yet it’s not a brick wall of sound. Again, it’s 3D like and holographic, with dynamic sounds layering. Soundstage being very dependant of ear tips choice, Kbear KB07 was the one that offer biggest and more coherent presentation.
Imaging is where i find the S12 underwhelming due to lack of precision in instrument separation, especially the static one that will benefit extra clarity and cleanliness. Yet, the layering do add a sens of separation and it’s impressive in that regard even if it would have benefit from higher transparency in timbre.
All in all, technicaly speaking, these are on par with near all other Planar apart the Tinhifi P1plus, which use a faster 10mm planar driver with less bass interference and better resolution and imaging.
COMPARISONS

VS TANGZU ZE TIAN WU:
The WU are more neutral balanced and warmer. Bass is less boosted and less impactfull, yet it seem faster in attack, better rounded and separated. It’s less prompt to slight bleed too and feel more textured and well define. Bass line and kick drum are better separated too.
Mids are leaner and fuller, timbre is smoother and even more natural than S12, it’s more transparent and higher in resolution even if less edgy in attack. Male vocal seem more recessed than the S12 tough and female vocal too even if presentation is richer, wider and less compressed.
Treble is very different here, the WU extract more details yet doesn’t put it in your face, micro definition is cleaner and highs have a bit more sparkle and air making the S12 feel a bit half cook in this area.
Spatiality is even more open with the WU, hint wider and taller but notably deeper.
This inflict positively to imaging, which is more accurate and precise due to more transparent timbre.
All in all, while i think people will perhaps find the WU more boring, it’s more refined in balance, more neutral and smooth with slightly superior technical performance especially in imaging department.
VS TINHIFI P1plus:
I don’t know if i’m crazy to love those P1plus that much since they are not praise anywhere, but i’m confident to say its the planar with best technical performance on the market right now and S12 don’t dethrone them in that regard. In fact, p1plus are the only planar i consider clean sounding, but first thing that hit me is how harder they are to drive since i need to put the volume 2 times higher than S12 using Moondrop Dawn dongle.
So, the P1plus is more vivid neutral and analytical, with lighter but more textured and well separated bass. Mids are more transparent and detailed, they open up in wideness more but have thinner timbre. Overall tonality is a bit colder too, notably higher in resolution and treble is way faster and more snappy, cleaner in definition and more sparkly and brilliant. It extract way more micro details too and add sens of air on top even more than both WU and S12. Note weight is a bit lighter yet attack have more edge to it. Instrument presence is better resolve with richer texture.
Spatiality is a bit more intimate, especially in term of wideness and tallness which is more closed, while deepness is infinitely deeper.
Imaging is where the P1plus destroy the S12, crisper, more accurate and precise in positioning, separation is clean and well define, making the S12 feel foggy.
All in all, the tonality of P1plus is leaner, colder and less full bodied and will please more the neutral head or mature audiophile but technical performance are notably superior. Yet, the S12 is more fun, full bodied and it’s euphonic timbre might feel more natural than slightly dryer timbre of P1plus.
Bonus! VS HZSOUND HEART MIRROR
HZ have a sharper, crisper as well as more neutralish W shape tonality, with greater sens of transparency and higher amount of micro details, so it feel more analytical-cold-neutral than bassier hint warmer in definition S12.
Cleaner is first thing that come to mind when going from S12 to HZM, since the S12 micro definition seem a bit blurred, softed, this permit to avoid harsh spike of HZM, which is more prompt to slight sibilance for ex.
And polemic will begin here, with my perception of bass quality. Here HZM sure have a more linear bass response with higher sens of flexibility, yet it’s less bodied and have lower mid bass slam, in the other hand, sub bass extend deeper and sub and kick bass are better layered and separated with the HZM, S12 offer warmer bass that tend to get mixed togheter. Let say S12 is more about physical impact that definition and presence, whih is clearer with HZM.
Mids are crisper and sharper as well as thinner and more transparent. Resolution of mid range is higher too, but note weight is lighter with HZM. Overall mid range is more euphonic-analogish-warmish with the S12.
Treble is very different, notably more crisp and sparkly with the HZM, bit thinner yet with more snap and air on top too. Acoustic guitar will be all about extra low harmonic and have less bit and brilliance, yet fuller body with S12. Resonance feel more damped too. We have less loudness spike than HZM so its smoother.
Spatiality is very different with these, the S12 is notably more open and holographic, yet not as deep and clean as HZM.
This translate in more precise accuracy for both layering and instrument separation for the HZM even if it feel strangely a bit more compressed.
Tonaly wise, musicality is easier to enjoy with the S12, while I would say technical performance are superior with HZM, since imaging and resolution is better as well as attack control and definition accuracy.
CONCLUSION

The Letshuoer S12 hype is legit since these planar IEM hit sweet spot between a fun lively tonal balance and decent technicalities only planar driver can deliver with such layered dynamic.
It’s this type of energic V shape tuning that isn’t overly warm or bright, and don’t offer recessed vocal or mid range.
The presentation is full bodied and impactfull, with fast attack that have a smooted edge to it to avoid agressive spike.
It’s this type of IEM that add weighty dynamic to your music and offer a versatile tonality that can deal with everything but extremely demanding busy music that will need sharper crispness and better sens of imaging.
Simply put, its a fun ride yet not a guilty pleasure because of great macro resolution, good timbre for a planar and full dynamic range that doesn’t omit presence of mid range.
I think S12 represent the revival of Letshuoer company, and sure still worth a buy even if the S12 Pro is coming, since it’s very same IEM but with a modular cable upgrade.
For a more laid back musicality, i would choose Tangzu Ze Tian Wu, for a crisper cleaner mroe analytical one i will go Tinhifi P1plus and for a fun versatil musicality with muscular bass, their no doubt the S12 have it’s special place!
Highly recommended!
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PS: I wanna thanks Letshuoer for finaly letting me test one of their product as well as offering a S12 Pro for Chifi Love giveaway. I’m not affiliated to this company and keep my 100% freedom of judgment as always.
You can buy the S12 on sale for 134.10$ from Official Store here:https://letshuoer.net/products/s12-hifi-earphones-planar-iems?fbclid=IwAR3n7hcHUMYe9DZgAeIQrWGexPSOmHt5B_n-sWXnKEPFiLM0S9A7JmdhC38