Dark Mode On / Off

Letshuoer S15 IEMS – Looks Blue, Sounds Good

Letshuoer S15 IEMS – Looks Blue, Sounds Good

Letshuoer S15 is a $329 USD pair of IEMs or In-Ear Monitors with a Third Generation 14.8mm Planar Magnetic Driver, and a Passive Filtering Module, designed for both comfort and sonic quality. Today we will review the S15 and compare them to other similarly priced IEMS we recently reviewed, including ThieAudio Hype 4 (399 USD), Westone MACH 40 (600 USD), Jomo Audio P3 Percussion (425 USD), and iBasso IT05 (299 USD). 



Letshuoer is a popular company from China, and S15 is a planar magnetic driver based IEM, with a nice default cable, along with a price tag to keep your pockets warm and cozy, akin to their mid centric and sweet sound. As an Amazon Influencer, I earn from qualifying purchases, and using the purchase links in my reviews helps me maintain this website and Youtube Channel. Letshuoer has provided the sample for this review, in exchange for my honest opinion.

PROs – Musical and fluid sound, Excellent comfort, Modular cable, Pleasing voicing, Smooth textures, Good Dynamic handling, Zero distortion regardless of the listening volume, Nice transport case, Cable quality is top notch, Two type of eartips, three sizes of each, intimate and colorful sound, very fun to listen to, sonically matches well with most sources. 

Cons – Voice-centric tuning not for everyone, hard to drive. 


Product Link

You can grab one here – https://amzn.to/3KxZnKJ


Build Quality/Aesthetics/Fit/Comfort

Letshuoer S15 bears a planar magnetic driver cyanide, and it is the third generation developed by Letshuoer, which is actually one of the backbones in the audiophile industry, as they develop new tech and new drivers. Besides the huge 14.8mm planar driver, we also have a 6mm R-Sonic passive filtering module. 

The shape of S15 is very smooth, and the body has a velvety touch feeling to it, which is really comfortable to hold in hand, and feel touching your ears. The shells are made by HeyGears, which has been seen before here, so you can expect great ergonomics and comfort, plus a reliable shell that has no mismatched parts, loose or open edges, and a product that will survive for many years. 

The shell face is made of aluminum, while the cable has 216 strands of Silver-Plated Monocrystalline Copper. The cable is a big highlight for the IEMS, as it has modular jack connectors, and will be useful regardless of the source you’re using. The cable is somewhat heavy, thick, and feels reliable, looks beautiful, and is good at canceling microphonic noise. 

Speaking of canceling, S15 does not isolate very much from the outside noise, but does not feel too open either, offering a secure seal. I am getting around 20 dB of passive noise isolation, but I am having a hard time driving them, as S15 is harder to drive than IE900, and while quickly switching between them, I need more volume for S15 to play well. My comfort with the S15 is great, as I have no driver flex, no void, but a comfortable IEM that is a bit large, but never feels weird or heavy. 

To drive the S15 I have used a selection of sources including Hiby R4, Creative Sound Blaster X5, HIFI Walker H2 Touch PRO, Dethonray Listening M1, iBasso DX260, and FiiO Q15. S15 does not seem sensitive to hissing or source noise, and it is not very sensitive to source signature and tuning either, always sounding musical, happy, clean and open, at most needing a source with a strong bass, and a crisp treble, since it got the sweet mids. 


Sound Quality

Overall Signature – There are two types of tips, three sizes of each included in the package with S15, and they are called Vocal and Balanced. The Vocal one is a thinner, boomy and bloomier sounding eartip, which offers really nice comfort, but sounds too warm and smooth for my taste, and with S15 already having a forward midrange, it makes them a bit too mid-centric for my taste. This means that I’ve been using the balanced eartips for most of my testing, and the sound is beautifully musical, playing a really nice guitar tone, keeping voices natural and clean, music free of grain, wide and well layered, although I would call the whole presentation cohesive rather than surgically separated. All instruments blend musically together, and S15 sounds and feels like the sweetest, most musically coherent IEM you can find in the midrange. Ironically, I have just reviewed the Sivga Nightingale, and it is still fresh in my mind, both IEMs sounding oddly similar to each other, so you will find some similarities between them. 

Bass – Letshuoper knows that a bit of bass is needed for an IEM to not sound too hollow, so S15 brings a bit of bass, more than what is absolutely neutral, enough to call impact and punch in pop songs, but it is not a bass heavy IEM by any means, most energy being found in the midrange. This being said, the bass is nicely layered, it is fluid and doesn’t bring a lot of grit, or texture, but it does have most of the energy around 50 Hz, has strong presence down to 35 Hz, and the 100 Hz is not overly strong, just enough to be fun and bring a bit of warmth to most songs. The bass is rendered so nicely that I find myself pumping up the volume with S15 to get more of it. 

Midrange – Letshuoer placed all their money on the midrange, and they created an IEM with a sweet, cohesive tuning, female voices such as that of Marine sounds angelic, sweet and juicy, while guitars are simply brilliant and colorful. Male voices are deep and realistic, S15 handling most musical information really well. It does tend to render sweet and higher pitched voices with more energy, so expect Takanashi Kiara to sound more forward than Mori Calliope, for example, something which is noticeable in their collaboration song Fire N Ice. A smooth texture helps give a relaxed, and fluid sound to all instruments, synths, guitars, everything just sounds playful and pleasing. 

Dynamics / PRaT / Textures – Despite having a low amount of texture, S15 sounds fairly balanced in the dynamics, it is not loose nor compressed, it brings the punch in pop and electronic songs, but allows classical to have a high dynamic range, handling both really nicely. 

Soundstage – S15 is mid centric, which means it can bring voices really close to the listener and sound intimate, but it seems to react differently to different songs, and rather it paints them accurately. For example music which is designed to sound really wide sounds wide and open, for example Billie Eilish – Lost cause sounds big, wide and well separated. This being said, songs which are intimate will be really intimate, and especially sweeter female voices will be projected close to the listeners, in songs like Futakuchi Mana – Datte, her voice is really close and intimate, and most of the song happens right around you as the listener. 

Volume Control – Letshuoer S15 handles volume perfectly, the sound is very similar across all volume levels, and it also can handle extremely loud volumes with zero distortion, showing great ability from the driver to keep sound distortion-free and precise at all volumes. 

Treble – At first, it feels like S15 will have a smoother treble, as the texture of the treble follows the same response as the mids and the bass, and it is smooth, but S15 can paint both air and sparkle nicely, the treble extends up to 20 kHz perfectly fine, but you can expect a fatigue-free listening session, as the treble gets intense only if the song is really bright, like Infant Annihilator, but even on metallic, I never felt any kind of fatigue from them. 




Letshuoer S15 vs Thieaudio Hype 4 (329 USD vs 399 USD)

Build – Hype 4 looks a bit more interesting with their colorful shells, but S15 is a more solid IEM, larger, and with an aluminum shell, S15 is less prone to scratches and smudges. The actual wearing comfort is comparable between the two, and both come with high quality cables. Hype 4 is more sensitive to source noise, to source tuning and sound. S15 is harder to drive and requires more power, but it is within what most portable sources will offer. 

Sound – Sonically, S15 is smoother, softer, and has a stronger, punchier bass. Hype 4 also has a good bass, but S15 can produce more punch, especially with songs that have a lot of low-end volume recorded, while Hype 4 is more detailed, can reveal more information from a song, at the cost of the whole sound having more grain and being far less relaxed and more fatiguing than S15. While I did find comments on Hype 4 sounding either fatiguing or unnatural for how much detail they reveal, I never found any negative comment on S15, as most listeners found this kind of grain-free, musical and smooth sound pleasing. Between the two, I would grab Hype 4 if you’re a detail addict and want the utmost resolution possible and I would grab S15 for a relaxed listening experience and for a smoother sound, but still detailed and very musical. 


Letshuoer S15 vs Jomo Audio P3 Percussion (329 USD vs 425 USD)

Build – P3 percussion has a smaller body, with a slightly more comfortable shell, and a thinner cable, but just as strong. S15 has a more premium cable, which is modular, and while the comfort is about equal, S15’s shell is larger, which could be an issue for those with smaller ears. It is easier to drive p3 percussion, but it is a bit more sensitive to source noise and to source signature, relying more on source synergy to sound good. S15 is less sensitive to source in general and needs more volume. 

Sound – Sonically, S15 is softer, more gentle, and more grain free, but has less impact and less punch than P3, which paints impact and punch with the utmost precision. The midrange is more natural as presented by S15, especially sweeter, higher pitched female voices, while P3 gets the drum and snare sound perfectly, pulling back the voices a bit in the process. P3 Percussion is much better for a monitoring instrument, or if you need the best drums and percussion precision, while S15 is a vocal centric earphone that sounds great with everything, including all music styles, being relaxed enough to make death metal enjoyable, detailed enough to reveal intricacies in classical, but also sweet enough to play well with vocal centric music.  


Letshuoer S15 vs iBasso IT05 (329 USD vs 299 USD)

Build – The shape of the two is actually not very similar, as IT05 is much smaller, but the cable is very similar, both having a similarly thick, heavy and just similarly looking cable. The cable of IT05 is also modular, and the package is a bit more premium, with a metallic transport case, and a more solid package, but the comfort is equal. Driving IT-05 is easier, but it is more sensitive to source noise. 

Sound – You really couldn’t go much farther away from S15 in terms of sonics than It05, as they are exactly at the opposite ends of the sonic spectrum. IT05 is V-Shaped, powerful, with a dominant sub-bass, a lush midrange and a sparkly, strong treble, U-Shaped at the extremities, which pushes an entirely different presentation from S15 which is mid centric and pulls on the extremities, allowing voices to be the central element in music, while sub bass, bass and upper treble shimmer are toned down. 


Letshuoer S15 vs Westone Mach 40 (329 USD vs 600 USD)

Build – Westone has a much smaller earphone here, with a much thinner cable, a 3.5mm single ended jack for the source, and a rare connector between the cable and the IEM, which makes getting an aftermarket cable rather complicated. S15 feels gigantic next to Westone in general, but the comfort is actually a bit better on S15, as the bore length is shorter, so it does not have to go quite as deep in your head. Mach 40 and all westone IEMs offer a higher degree of passive noise isolation, are easier to drive, but more sensitive to source noise. The package of Westone Mach 40 is more professional, at the literal level, as it comes with a pelican case, while S15 has a more colorful package. 

Sound – After getting a good seal on the Westone, which can be a bit tricky for newcomers, as it comes with a huge number of tips and it requires fiddling, Mach 40 sounds more precise, more dry and can reveal more detail from music, all while having a similar degree of midrange presence. S15 has a stronger bass, a punchier bass, better dynamics and more impact, while sounding more relaxed and cleaner in general. Westone IEMS are great for monitoring, but can be a bit too precise, in the same sense Hype 4 is, while S15 sounds perfect for any music lover looking to lean back and relax, enjoy a pleasing listening experience. 


Value and Conclusion

When I started writing today’s review, the price of S15 was 329 USD, but I can find it now at 299 USD, and the value is great, this is a small price to pay for the kind of special musicality and pleasing sound it can produce. While the tuning won’t be for everyone, those who are seeking it, will find true composure in the comfort and sound of S15. 

At the end of the day if you’re looking for a grain-free sound, an IEM that will match really well with all of your sources, excellent comfort and ergonomics, and for a modular cable, all at the pocket-friendly price of 299 USD, Letshuoer S15 is a fully recommended product and an earphone I love using to listen my favorite tracks with. 


Product Link

You can grab one here – https://amzn.to/3KxZnKJ


Technical Specifications 

Model – S15 Wired In-Ear Monitor

Chassis Material – 3D printed resin

Material of Faceplate – Anodized aluminum

Frequency Response – 20Hz~40kHz

Impedance – 30Ω

Sensitivity – 106dB

Audio connectors – 2.5mm/3.5mm/4.4mm interchangeable connectors

Cable – 1.2m 216-strands silver-plated monocrystalline copper

Driver – 14.8mm planar driver + 6mm passive filtering module

--- Please remember to stay safe, and always have fun while listening to music!---

 - If you have a dime to spare, please donate, and help us! It would make the day brighter for me and my wife- 

Full Playlist used for this review

We listened to more songs than those named in this playlist, but those are excellent for identifying a sonic signature.  I recommend trying most of the songs from this playlist, especially if you’re searching for new music! The playlists are different for Spotify, Tidal and Youtube, and based on the songs I enjoy and are available on each!




--- Contact Us ---

Leave a Reply

Your email address will not be published. Required fields are marked *

Copyrighted (C) to www.audiophile-heaven.com