LetShuoer S15 IEM Review



LetShuoer S15 IEM Review



LetShuoer (former Shuoer) is a Chinese company located in Dongguan, Guangdong, China and is specialized in design and development of portable audio equipment’s such like Universal & Custom In-Ear Monitors and USB DAC/Amplifiers.

The Letshuoer S15 is an In-Ear Monitor that features pretty unique Acoustic Structure that consists of a 14.8mm dual chamber Planar Magnetic Driver with a 6mm “R-Sonic” passive filtering module. The S15 also boasts a lightweight and comfortable shell that is 3D printed by HeyGears, a leading company in the field of 3D printing. The S15 comes with a High Purity 216 Strand Silver-Plated Monocrystalline Copper wire cable that has 3x interchangeable connectors (2.5mm, 3.5mm, and 4.4mm) to suit different device interfaces.



I would like to thank LetShuoer for providing me the S15 In-Ear Monitor as review sample. I am not affiliated with LetShuoer or any third person beyond this review and all these words reflect my true, unaltered opinions about the product.


Price & Availability:

The actual price fro the LetShuoer S15 Planar Magnetic Driver IEM is 329.00 US$. More information’s can be found under the link below;


Package & Accessories:

The LetShuoer S15 came inside a rectangular grey box with the LetShuoer branding on the top that was wrapped with a cardboard in the same grey color that has some product related brandings on the top.

Inside the box are the following items/accessories;

  • 1 x pair of LetShuoer S15 In-Ear Monitors
  • 1 x 2-Pin Detachable Cable with Interchangeable Connector Design
  • 3 x Types of Interchangeable Connectors (3.5mm SE, 4.4mm & 2.5mm Balanced Plug)
  • 3 x pairs of Balanced Silicone Ear Tips (S, M, L)
  • 3 x pairs of Vocal Silicone Ear Tips (S, M, L)
  • 1 x Storage Case
  • 1 x Some Print Materials


Design & Build Quality:

The Letshuoer S15 has a lightweight 3D-printed shell by HeyGears, a leading name in the field of 3D printing. The main housing comes in a sleek blue finish, while the faceplate features a fancy CNC-carved aluminum alloy panel in grey, adding a touch of elegance.

The S15 features a unique acoustic structure consisting of a new 3rd Generation 14.8mm dual-chamber planar magnetic driver paired with a 6mm “R-Sonic” passive filtering module. This Dual Acoustic Tube design utilizes a special crossover circuit for enhanced audio performance.

Each monitor features a low-profile sound nozzle with a metal mesh on top to prevent dust and earwax buildup. L/R markings, Letshuoer branding, and two pressure relief vents complete the design.

On the top of the monitors is a 0.78mm diameter 2-Pin female connector interface that offers a pretty tight and secure connection.

The S15 comes equipped with a 4-core, 216-strand high-purity silver-plated monocrystalline copper wire cable. The braided design with soft PVC insulation ensures flexibility and durability.

The 2-pin connectors boast metal housing with clear left (transparent) and red right color indicators. Heat-shrink ear guides offer comfort on the go.

The cable has a metal Y-splitter and a transparent plastic chin slider.

A standout feature is the interchangeable headphone plug design, becoming a new standard for in-ear monitors. The detachable cable includes 3.5mm single-ended, 4.4mm balanced, and 2.5mm balanced adapters, offering versatile connectivity options.


Comfort & Isolation:

The LetShuoer S15 is a very lightweight in-ear monitor with a very ergonomic shape that fits perfectly into my ears with a medium-sized ear concha, while the passive noise isolation of the monitors is sufficient for the use in relatively noisy environments such as a bus or a train.


Pairing & Drivability:

The LetShuoer S15 is a relative easy to handle IEM with its impedance of just 30Ω and a sensitivity of approx 106dB. This makes it compatible with sources like USB DAC/AMP Dongles like the iBasso DC06 Pro. However, like most IEM’s that are powered with a large (14.8mm) Planar magnetic driver the S15 benefits from a more powerful source like the HiBy R6 II Pro or the FiiO M11 Plus ESS, especially when paired with over the 4.4mm Balanced output.


Technical Specifications:

  • Driver Configuration   : 14.8mm Dual Chamber Planar Magnetic Driver + 1x 6mm Passive Radiator
  • Frequency Response : 20-40 kHz
  • Sensitivity                   : 106dB/mW @1kHz
  • Impedance                 : 30Ω
  • Connector Interface   : 0.78mm dia. 2-Pin
  • Plug                            : 3.5mm single-ended, 4.4mm and 2.5mm balanced adapters



Equipment’s used for this review:

  • IEM’s             : LetShuoer S15, TINHIFI P2
  • Sources         : Quloos MUB1, HiBy R6 II Pro, FiiO M11 PLUS ESS Sabre, iBasso DC06 Pro


Albums & Tracks used for this review:

  • Norah Jones – Come Away With Me (Flac 24bit/96kHz)
  • Adele – My Little Love (Deezer HiFi)
  • Sarah McLachlan – Angel (Flac 24bit/48kHz)
  • Sertap Erener – Aşk (Flac 16bit/44.1kHz)
  • Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
  • Diana Krall – So Wonderful (DSF)
  • Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
  • Michael Jackson – Billie Jean (Flac 24bit/96kHz)
  • George Michael – Don’t Let the Sun Go Down on Me (Flac 24bit/192kHz)
  • David Bowie – Heroes (Flac 24bit/192kHz)
  • Elton John – Rocket Man ((Flac 24bit/96kHz)
  • Barry White – Just The Way You Are (Flac 24bit/48kHz)
  • Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
  • Sting – Englishman in New York – (Flac 24bit/48kHz)
  • Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • Radiohead – Live in Berlin “Album” (Deezer HiFi)
  • Radiohead – Pyramid Song (Deezer HiFi)
  • U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
  • Muse – Hysteria (Flac 24bit/96kHz)
  • Red Hot Chili Peppers – Nobody Weird Like Me (Flac 24bit/48kHz)
  • Michael Jackson – Billie Jean (Flac 24bit/96kHz)
  • Bear McCreary’s – Valkyries (Deezer HiFi)
  • Bro Safari, UFO! – Drama (Deezer HiFi)
  • Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
  • Daft Punk – Doin’ it Right (Flac 24bit/96kHz)
  • Lorde – Royals (Flac 24bit/48kHz)
  • Massive Attack – Angel (Flac 24bit/48kHz)
  • Toutant – Rebirth (Deezer HiFi)
  • Gogo Penguin – Raven (Flac 24bit/192kHz)
  • Gogo Penguin – Murmuration (Flac 24bit/192kHz)
  • Portishead – It Could Be Sweet (Spotify)
  • Max Richter – On the Nature of Daylight (Flac 24bit/96kHz)
  • Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
  • Tchaikovsky – Symphony No. 5 (Flac 16bit/44.1kHz)
  • Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
  • Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
  • Clair de Lune – Claude Debussy (Spotify)
  • Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Deezer HiFi)
  • Miles Davis – So What (Deezer HiFi)
  • Otto Liebert& Luna Negra – The River (Flac 24bit/192kHz)
  • Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
  • Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
  • Metallica – Dyers Eve (Flac 24bit/96kHz)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Opeth – Windowpane (Flac 16bit/44.1kHz)
  • Megadeth – Sweating Bullets (Tidal Hi-Fi)
  • Rush’s – Tom Sawyer (Flac 16bit/44.1kHz)
  • Slayer – Angel of Death (Spotify)
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Yosi Horikawa – Bubbles (Spotify)



The Sound:

The LetShuoer S15 is a pretty interesting IEM that features a 14.8mm dual-chamber planar magnetic driver paired with a 6mm “R-Sonic” passive filtering module that has been generating a lot of buzz in the audiophile community. With its sleek design and promise of a smooth, balanced sound, the S15 has the interest of many reviewers and listeners alike. But how does it actually sound? Let’s take a deep dive into the S15’s sound signature, exploring its bass, midrange, treble, and soundstage performance.

This review has been written after a burn-in period of 50 Hours. I have used the stock balanced silicone ears tips and the stock cable with the 4.4 mm Balanced Headphone Adapter that is included to the package. My main source was the HiBy R6 II Pro (DAP) and FiiO M11 Plus ESS Sabre (DAP) and the Quloos MUB1 (DAC/Amplifier).



Bass / Midrange / Treble / Soundstage & Imaging:

The LetShuoer S15’s bass response is immediately impressive. It’s present and impactful without being overbearing, with a nice sub-bass extension that adds warmth and body to the low end without bleeding into the midrange. This can be heard on tracks like Massive Attack’s “Angel”, Lorde’s “Royals” or Daft Punk – Doin’ it Right where you can hear a satisfying thump without obscuring the other elements of the mix. The bass is also well-textured and nuanced, with good detail and control.

On Bear McCreary’s “Valkyries”, the bassline is tight and articulate, even at higher volumes. The bass doesn’t get muddy or too boomy, thanks to its excellent control and speed of the 14.8mm Planar Magnetic Driver. This makes the S15 a great choice for bass-heavy genres like hip-hop and EDM, but it also shines with acoustic music, adding a touch of weight and foundation to the cello and double bass.

The midrange of the LetShuoer S15 is smooth and natural, with good amount of clarity and detail retrieval. There’s no emphasis on any particular part of the midrange, which allows instruments and vocals to be presented faithfully. Vocals are presented relative upfront and intimate, with a slight upper midrange emphasis that adds a touch of brightness and airiness. This emphasis can sometimes make sibilant sounds a little noticeable while listen to poor recorded tracks, but it never becomes harsh or fatiguing.

The midrange also has good separation, which makes it easy to follow individual instruments in complex mixes. On Radiohead’s “Pyramid Song,” the acoustic guitars and piano are distinct and clear, even when layered with other instruments. The lower midrange is also well-represented, giving instruments like guitars and drums a natural body and weight.

The treble of the LetShuoer S15 sounds smooth and non-fatiguing. It’s not rolled off, but it’s also not overly bright or peaky. This makes it great for long listening sessions without causing ear fatigue. The upper treble region of the S15 is extended and airy, without being overly bright or peaky. There’s a good amount of sparkle and detail in the cymbals and hi-hats, but it never becomes harsh or fatiguing.

In songs like Miles Davis’ “So What” the trumpet has a nice bite without being piercing, and the cymbals shimmer gently in the background. The general extension of the treble range is on a good level, reaching all the way up to 20kHz. This gives the S15 a sense of air and space. However, some listeners may find the lower treble region a little rolled-off compared to some brighter IEM’s.

The LetShuoer S15’s soundstage is surprisingly wide and spacious, where instruments are well-separated and positioned, creating a sense of immersion and depth. However, the soundstage is not artificially wide, and it never feels like instruments are coming from outside of your head.



LetShuoer S15 versus TINHIFI P2:

The TINHIFI P2 shows a sub-bass emphasis that lends warmth and impact to the lower frequencies. While the LetShuoer S15’s sub-bass is slightly less pronounced, it shines in terms of decay, clarity, and control, avoiding muddiness and midrange bleed. Moving into the mid-bass, the P2 retains its warmth, delivering a smooth and pleasing response. However, the S15 takes the lead with its tighter, punchier delivery, offering a superior sense of transparency and quickness that tackles complex bass passages with ease.

Both IEMs deliver clear and well-defined midranges, offering a decent level of information. The P2’s lower midrange receives a slight warmth, particularly noticeable with male vocals and instruments like strings, brass, and pianos. However, the S15 outshines it in this area with its superior transparency and resolution. The S15’s upper midrange boasts more presence, resulting in a brighter and more neutral presentation that excels at bringing out detail in complex mixes.

Both IEMs offer well-extended and airy treble. The TINHIFI P2’s lower treble is smoother and less energetic than the LetShuoer S15’s. While the S15’s treble range shines with its detailed and resolving nature, bringing out cymbals and hi-hats with clarity, the P2’s treble between 10-20 kHz can sound slightly unnatural and harsh compared to the S15’s smooth and natural presentation.

Both IEMs create an airy and spacious soundstage atmosphere with good instrument and vocal separation. The LetShuoer S15 takes the lead in terms of soundstage depth and height, while the TINHIFI P2 edges it out in width.


The LetShuoer S15 is a compelling in-ear monitor that defies expectations with its unique combination of technical prowess and musicality. Its 14.8mm planar magnetic driver delivers a bass response that’s both impactful and nuanced, while the smooth and natural midrange faithfully presents vocals and instruments without sacrificing detail. The treble, while not overly bright, retains enough sparkle and extension to create a spacious and immersive soundstage. The combination of its lightweight 3D-printed shell, high-quality cable, and interchangeable connectors make the S15 a versatile and practical choice for audiophiles on the go.


Pros & Cons:

  • + Impressively impactful and nuanced bass
  • + Midrange faithfully presents vocals and instruments
  • + Treble that is not overly bright, while retains enough sparkle and extension
  • + Very lightweight and comfortable 3D-printed shell
  • + I Love the Minimalistic Design
  • + Great cable with interchangeable connectors
  • + Rich Set of Accessories


  • – Slightly rolled-off lower treble
  • – Some sibilance in the upper midrange on poorly recorded tracks
  • – A bit Pricy


Thank you for the Read!








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