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Letshuoer S12 Ultra vs Sennheiser CX 350BT: 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.

Score breakdown

Each axis is a 0–10 blend of what reviewers scored, not a lab measurement.

Neither pulls ahead overall - they trade wins across the measures.

  • Letshuoer S12 Ultra
  • Sennheiser CX 350BT
HearWiki score
83
52
Sound
8.6
6.7
Battery
-
7.2
Calls
-
6.2
Value
8.9
-
Price (USD)
$170
$94

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

The Letshuoer S12 Ultra is 5 years newer, but it is 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. For 5 years between them, that is a thin return - treat this as a restyle rather than a new platform.

  • S12 Ultra20255 yr newer
  • CX 350BT2020

Specifications

S12 UltraCX 350BT
Type
Wired IEMs
Wired IEMs
Price (USD)
$170
$94
HearWiki score
83
52
Released
2025
2020
Availability
Sold new
Discontinued
Driver
1 planar magnetic
9.7 mm dynamic
Driver type
planar
dynamic
Driver configuration
1 planar magnetic
-
Driver size
14.8 mm
9.7 mm
Drivers per side
1
1
Frequency response
-
17 Hz - 20 kHz
Impedance
16 Ω
28 Ω
Sensitivity
-
112 dB/mW
Bluetooth
-
5.0
Codecs
-
SBC, AAC, aptX, aptX Low Latency, LHDC
Multipoint pairing
-
Yes
Wireless range
-
10 m
Battery life
-
10 h
Full charge time
-
90 min
Wireless charging
-
No
Active noise cancelling
-
No
Weight
-
12 g
Water resistance
-
none
USB-C
-
Yes
Microphones
-
1

What reviewers said

Letshuoer S12 Ultra

The Letshuoer S12 Ultra is a wired in-ear monitor that delivers Hi-Fi sound through a single 14.8mm planar magnetic driver housed in a lightweight aluminum-alloy shell. Aimed at music enthusiasts, it offers the signature planar-driver clarity and detail of the S12 series in a refreshed design, without any active noise cancellation or wireless features. Priced around $169, it's a straightforward, high-performance option for wired listening.

  • Pro:Detailed and fast planar magnetic sound
  • Pro:Lightweight and durable aluminum-alloy build
  • Pro:Accurate bass response with low distortion
  • Con:Requires a wired connection, no wireless freedom
  • Con:No active noise cancellation for noisy environments
  • Con:Open-back style may leak sound in quiet settings

Sennheiser CX 350BT

The Sennheiser CX 350BT are compact wireless in-ears that prioritize reliable performance and long battery life for daily use. They offer a natural, detailed sound with strong codec support, plus multipoint connectivity for seamless switching between devices. While they lack noise cancellation and water resistance, their lightweight build and quick charging make them a practical choice for commuters and casual listeners.

  • Pro:Long 10-hour battery life with quick USB-C charging
  • Pro:Supports multiple high-quality codecs including aptX and LHDC
  • Pro:Multipoint Bluetooth allows connection to two devices at once
  • Con:No active noise cancellation or water resistance
  • Con:Treble can occasionally sound sharp or sibilant
  • Con:Wearing comfort may not suit all ear shapes

Summaries are AI-condensed and paraphrased from published reviews and specs - not original hands-on testing. More on our method.

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New comparisonLetshuoer S12 UltraSennheiser CX 350BT