The Letshuoer Astralis is a single-driver in-ear monitor using a 15.5mm ring-type planar dynamic driver. It launched in the spring of 2026 at a price of 189 USD.
The S12 Ultra is the fourth generation of the S12 series. The S12 Ultra is equipped with a 14.8mm planar magnetic driver and is typically priced at 169 USD.
Both IEMs are similar in size and feature metal shells. I find them equally comfortable. They come with similarly looking high-quality cables featuring 0.78mm 2-pin connectors and an interchangeable 3.5mm/4.4mm termination plug system.
Both the Astralis and S12 Ultra come with a USB-C DAC/Amp in the box: the tiny but quite capable DT01 Pro.
My S12 Ultra review can be found here.
LETSHUOER ASTRALIS SPECIFICATIONS
- Driver: 15.5mm 5th-Generation proprietary ring-type planar diaphragm driver
- Impedance: 20 Ohms
- Sensitivity: 104dB
- Frequency Response: 20Hz~40kHz
- Chassis Material: Aluminum Alloy
- Cable: 1.2m detachable 216 x 0.05mm strands of silver-plated monocrystalline copper
- Cable connectors: 0.78mm 2-pin
- Cable termination: 3.5mm and 4.4mm interchangeable
- Ear tips
- Puck shaped storage box
- DT01 Pro 3.5mm to Type-C DAC amplifier included
Current price and availability:
LETSHUOER S12 ULTRA SPECIFICATIONS
- Driver: 14.8mm planar magnetic
- Impedance：16 ohms
- Sensitivity：101dB
- Frequency Response：20Hz – 40kHz
- Material: Aluminum alloy
- Cable: 1.2 m Silver-plated copper
- Cable connectors: 0.78 mm 2 pin
- Cable termination: 3.5 mm and 4.4 mm interchangeable jacks
- Ear tips
- Puck shaped storage box
- DT01 Pro 3.5mm to Type-C DAC amplifier included
Current price and availability:
LISTENING COMPARISONS
Associated equipment:
- Amplifier: Topping A90
- DAC: RME ADI-2 DAC FS
- Tips: SpinFit CP145
In The Mountains by Espen Eriksen Trio
The Astralis leans darker with more bass presence, while the S12 Ultra offers a crisper midrange and more energetic treble. The difference is not dramatic, but it is there.
Re-Melt by Tord Gustavsen
The S12 Ultra delivers crisper percussion and more energetic piano reproduction, while the Astralis is smoother and more laid-back overall, with a darker, warmer presentation and thicker, more substantial bass.
Teardrop by Massive Attack
The Astralis has more bass and a generally more laid-back delivery, with smoother mids and highs. The S12 Ultra is not radically different, but offers slightly less bass, slightly brighter vocals, and marginally crisper highs.
The Hidden Camera by Photek
Here they’re very similar. Again, the Astralis is a tad darker and creamier sounding.
Eye of The Day by Marta del Grandi
The biggest difference lies in the vocals, which are crisper and brighter with the S12 Ultra. It is not a huge difference, but it is noticeable. Both IEMs are relatively smooth and pleasantly warm nonetheless. Think of them as two different chocolate flavors.
Dancing in the Dark by Jørgen Dahl Moe
This classic Springsteen tune has never sounded quite this good. The vocals on this recording can be a bit crisp and aggressive, but neither IEM emphasises this, both remaining smooth and natural. The two are very close in overall presentation.
Spontaneous Compositorius by Thomas Agergard
Here too they are very similar. The saxophone is slightly crisper and brighter with the S12 Ultra, though the difference is not dramatic. The same applies to the percussion, which is also marginally crisper with the S12 Ultra.
Sandermosen by Maridalen
Both sound very good, with a nicely warm presentation, solid bass presence, and smooth mids and treble. The Astralis leans slightly more in this direction than the S12 Ultra, but the two are very similar overall.
Sujet Tabou by Renaudin and Cahours
A great duo featuring acoustic guitar, percussion and occasional vocals. The S12 Ultra is a tad crisper and sharper, while the Astralis is slightly darker and warmer.
Jambi by Tool
Even though they are quite similar, I prefer the darker and lusher Astralis, as its richer bass makes a real difference on this track.
Escape Route by Boris Blank
The difference is less pronounced here, with both sounding organic and dynamic, offering very good bass, and a midrange and treble that is neither overly crisp nor aggressive on either.
Summer 3 Vivaldi Recomposed by Max Richter
Here they are more different. The Astralis is markedly more laid back and smoother, which is not necessarily a good thing on this orchestral piece. The S12 Ultra has a crisper and brighter take on the music. However, once your brain has adjusted to the darker character of the Astralis, it is rich in detail and still offers a very good experience.
WRAPPING IT UP
Sound Signature
The Letshuoer Astralis and S12 Ultra are quite similarly tuned. Both have elevated bass and a relatively smooth midrange and treble. In direct comparison though, the Astralis has more bass and a darker and smoother tuning overall.
Treble
Both have relatively inoffensive treble, but the Astralis is smoother and darker when compared directly. The S12 Ultra has a bit more bite to it, even though it is much smoother than the previous iterations of the S12 series.
Midrange
The midrange is relatively similar, but the S12 Ultra generally has more upper midrange presence and comes across as slightly brighter and crisper overall.
Bass
Both have elevated bass quantity and very good quality, but when compared directly the Astralis mostly offers the most bass quantity of the two.
Soundstage and Imaging
Soundstage size and imaging performance are good on both and pretty much comparable across the board. There are some variations between tracks, but nothing significant.
Detail, Dynamics, and Timbre
The detail level is quite comparable, but I tend to find the Astralis a tad more refined across the board. The S12 Ultra is still very good, though.
Dynamics are very similar.
Timbre is also pretty similar, but as mentioned the S12 Ultra tends to be a bit more upfront and slightly brighter. I regard it as sounding more neutral than the darker and lusher Astralis.
CONCLUSION
Both the Letshuoer Astralis and S12 Ultra are well-tuned planar IEMs that share a relatively similar sound signature.
The Astralis leans darker and lusher with more bass presence and a slightly more refined overall presentation, while the S12 Ultra is a touch brighter and more neutral with crisper vocals and more energetic treble.
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