Wired IEMs
Letshuoer S12 Ultra
83Outstanding
$170
Full review dataLetshuoer S12 Ultra vs NF ACOUS NM20: which should you buy?
On aggregated review scores the Letshuoer S12 Ultra comes out ahead with a HearWiki score of 83. The full breakdown - sub-scores, specs and what reviewers actually said - is below.
Our pick: Letshuoer S12 Ultra - Outstanding overall at around $169.
Wired IEMs
NF ACOUS NM20
57Average
$120
Full review dataScore breakdown
Each axis is a 0–10 blend of what reviewers scored, not a lab measurement.
Letshuoer S12 Ultra leads on 3 of 4 measures.
- Letshuoer S12 Ultra
- NF ACOUS NM20
HearWiki score
83
57
Sound
8.6
6.1
Value
8.9
5.8
Price (USD)
$170
$120
Generation & platform
The scores rank quality. This is the other question: is the newer one actually newer technology, or the same platform in a new shell?
Same generation
Letshuoer S12 Ultra (2025) against NF ACOUS NM20 (2024). These are the same generation of hardware - nothing in the radio, the codecs or the noise cancelling separates them. Nothing separates them on convenience features either, so the choice comes down to tuning and price.
- S12 Ultra20251 yr newer
- NM202024
Specifications
S12 UltraNM20
- Type
- Wired IEMs
- Wired IEMs
- Price (USD)
- $170
- $120
- HearWiki score
- 83
- 57
- Released
- 2025
- 2024
- Availability
- Sold new
- Discontinued
- Driver
- 1 planar magnetic
- dynamic
- Driver type
- planar
- dynamic
- Driver configuration
- 1 planar magnetic
- -
- Driver size
- 14.8 mm
- -
- Drivers per side
- 1
- -
- Impedance
- 16 Ω
- -
- Sensitivity
- -
- 108 dB/mW
- Connector
- -
- 2-pin 0.78 mm
What reviewers said
Letshuoer S12 Ultra
The Letshuoer S12 Ultra is a wired in-ear monitor built around a single 14.8mm planar magnetic driver housed in a lightweight aluminum shell. It delivers the signature planar sound of the S12 line—fast, detailed, and punchy—in a refreshed design aimed at hi-fi enthusiasts. With a low 16-ohm impedance, it pairs easily with most sources, though it lacks any active noise cancellation.
- Pro:Fast, detailed planar sound with strong dynamics
- Pro:Lightweight and sturdy aluminum-alloy build
- Pro:Easy to drive thanks to low impedance
- Con:No noise cancellation or isolation features
- Con:Planar timbre may not suit all listeners
- Con:Cable and accessories are basic for the price
NF ACOUS NM20
The NF ACOUS NM20 is a wired dynamic-driver in-ear monitor designed as the follow-up to the NM2, catering to both studio and stage use. It features a custom MC2L-100P driver and a Clutter Trap acoustic system to deliver clear, balanced sound. With a 108 dB sensitivity and standard 2-pin connector, it offers reliable performance for monitoring applications.
- Pro:Accurate, neutral tuning suited for critical listening
- Pro:Efficient 108 dB sensitivity works well with most sources
- Pro:Interchangeable 2-pin cable adds versatility
- Con:No noise cancellation, so isolation relies on ear tips
- Con:Lacks wireless or Bluetooth convenience
- Con:May require a quality source to fully shine
Summaries are AI-condensed and paraphrased from published reviews and specs - not original hands-on testing. More on our method.
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