LETSHUOER S15 Review – Worth The Price?

The LETSHUOER S15 in-ear monitors have a third-generation planar magnetic driver with a diameter of 14.8mm. The S15 results from extensive research and technical optimization of planar membranes. Their structure also incorporates a 6mm passive radiator driver to optimize the planar driver and provide better dynamics and transient response.


This 6mm passive radiator driver accompanying the planar driver is based on R-Sonic Dynamic Harmonic technology. This passive radiator eliminates low-frequency excess, manages internal acoustic pressure, and ensures effective passive resonance, according to LETSHUOER.


The S15 incorporates a two-tube acoustic crossover system to ensure a smooth transition between bass, midrange, and treble. This brings transparency and rich stratification to the sound. The distribution of energy between the planar driver and the passive radiator also reduces distortion.


The S15 acoustic chamber was designed by Letshuoer in collaboration with HeyGears. It meets the highest standards of stability and comfort. The interior is specially designed to provide acoustic stability and a very low level of distortion. In addition, the exterior of the shell is made from a CNC-machined aluminum-magnesium alloy, sandblasted, and anodized for a soft, smooth surface.


To ensure perfectly stable transmission of the sound signal, a high-end cable made of 216 strands of silver-plated monocrystalline copper is supplied in the box. Standard 2-pin 0.78mm connectors are found on the earphones’ side, while a termination compatible with changeable connectors is found on the other side of the cable. You can choose between the following connectors: 3.5mm jack, 4.4mm jack, or 2.5mm jack. All connectors are angled at 90°.


What’s in the box

  • LETSHUOER S15 in-ear monitors
  • 2-pin 0.78mm cable with interchangeable termination.
  • 3.5mm 90° angled connector
  • 4.4mm 90° angled connector
  • 2.5mm 90° angled connector
  • 5 pairs of silicone ear tips.
  • Case


  • Sensitivity: 106dB
  • Frequency Response: 20Hz〜40kHz
  • Impedance: 30Ω
  • Chassis Material: 3D printed resin + Aluminum faceplate
  • Color: Blue and silver
  • Cable: 1.2m 216-strand silver-plated monocrystalline copper
  • Driver: 14.8mm Planar Driver + 6mm Passive Filtering Module
  • Price: $319

I would like to thank LETSHUOER for providing me with the review sample of the S15 Planar IEM.


One of the best-tuned IEMs for my taste. If you want to elevate the sub-bass more just remove the foam inside the nozzle (mod). You also get a slight elevation between 2.5KHz – and 6KHz as you can see in the graph.


The LETSHUOER S15 impresses with its excellent balance, transparency, and clarity. Its imaging is precise, creating a wide and lifelike soundstage. This IEM has a fast response and accurate decay across all frequencies while maintaining a smooth and enjoyable listening experience.

The bass is snappy and detailed, with superb control and good sub-bass extension. The mids are accurate with a nice bite and a slightly forward vocal presentation. The treble strikes a superb balance with good lower treble energy smoothly delivered and a well-extended and refined upper treble. The resolution is also quite impressive.


The source I used was FiiO’s new AK4499EX-powered K9 AKM DAC-AMP. And let me tell you the S15 needs a good source to shine.


The LETSHUOER S15 offers precise and controlled bass. While it may lack some punch compared to dynamic drivers, it excels in control and minimal distortion even with heavy bass tracks. The S15 delivers agile and clean bass with a balanced quantity.

The bass is well-balanced, not favoring either the sub-bass or mid-bass, both of which have excellent extension and rumble for a planar driver. The mid-bass has just the right amount of quantity with great detail and texture.

The S15’s bass is not only fast, but it can also match the speed of the fastest tracks. Moreover, it’s not a dull bass; it has a touch of naturalness to it.



The LETSHUOER S15 mids align well with the overall signature, offering an organic blend of reference. The sound is evenly balanced with no specific focus in the range, although there may be a slight emphasis on vocals.

The midrange is clear and transparent, just like the other frequencies. Both male and female voices have good depth. The midrange is not too thin or too thick. The balance of tones is great, it sounds natural and not overwhelming. This setup creates a precise and accurate midrange that doesn’t sound dull. The overall sound never feels artificial and maintains an organic feel across all frequencies.


The lower mids are not very pronounced, but they are not recessed either. I like the balanced body and weight, it’s not too thin which can affect clarity. I prefer notes to have a realistic weight, and the LETSHUOER S15 delivers on that front with a hint of organic sound in its tuning that I find very pleasing.

The upper mids strike a balance between safety and bite. I prefer my upper mids to be free from harshness, yet still have a touch of bite for a strong presence in acoustic guitars, hi-hats, snare drums, and electric guitars. The S15 achieves this delicate balance effortlessly.


The S15 produces lively and dynamic treble, providing brightness and clarity without causing tiredness or harshness. It accurately reproduces high treble, effortlessly reaching the highest notes. The level of detail and clarity in this range is remarkable, making it one of the top performers in its price category.


The S15 has a lively upper treble. LETSHUOER focused on tuning it to produce a resolving sound. The highs are raised, but they don’t reach the point of being harsh. The upper harmonics are beautifully resolved. The presentation is clear, detailed, and distinct. It adds an extra layer of resolution and vibrancy, benefiting a majority of popular genres. The excitement and vividness of the S15 are attributed to both its bass and this particular range.


Overall, the 15’s planar sound also excels in technicalities which we are going to talk about next.


The LETSHUOER S15 maintains a strong technical capability. Demonstrating excellent agility and control. It handles crowded stages, and complex passages with multiple instruments very well due to its airy and spacious presentation, maintaining clear separation between instruments.

The S15’s planar diaphragm makes it ideal for reproducing all styles of music. Thanks to their wide soundstage, they offer a detailed and precise reproduction. Its presentation feels dynamic, vivid, and full of energy, offering an immersive experience that appeals to a broad spectrum of music genres.


Despite being a detailed IEM, the S15 is surprisingly forgiving. It does not over-emphasize the imperfections of your sources or tracks.


The LETSHUOER S15 offers excellent tonal balance, dynamics, detail, and clarity. It accurately reproduces tones and has an organic and inviting sound. If you want a well-built IEM that provides accurate and musical sound, the S15 delivers impressive resolution and remarkable tonal accuracy throughout the range.


To summarize, the LETSHUOER S15 is an excellent option for true music lovers. It provides an engaging and lively sound across different music styles, with its improved bass, vibrant midrange, and clear treble. Not only is the S15 technically impressive, but it also delivers a fun and captivating listening experience. The answer is yes, the S15 is worth the asking price.