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7Hz Eternal vs Letshuoer S12 Ultra: 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.

Letshuoer S12 Ultra leads on 4 of 4 measures.

  • 7Hz Eternal
  • Letshuoer S12 Ultra
HearWiki score
43
83
Sound
5.5
8.6
Value
3.0
8.9
Price (USD)
$250
$170

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 3 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 3 years between them, that is a thin return - treat this as a restyle rather than a new platform.

  • Eternal2022
  • S12 Ultra20253 yr newer

Specifications

EternalS12 Ultra
Type
Wired IEMs
Wired IEMs
Price (USD)
$250
$170
HearWiki score
43
83
Released
2022
2025
Availability
Discontinued
Sold new
Driver
14.5 mm dynamic
1 planar magnetic
Driver type
dynamic
planar
Driver configuration
-
1 planar magnetic
Driver size
14.5 mm
14.8 mm
Drivers per side
-
1
Impedance
30 Ω
16 Ω
Weight
6 g
-
Connector
MMCX
-

What reviewers said

7Hz Eternal

This wired IEM uses a single 14.5 mm dynamic driver with an LCP diaphragm, housed in an aluminum shell topped with a sapphire-glass faceplate. At just 6 grams per earpiece, it's built for long, comfortable sessions, making it a solid pick for desk or home use. With a 30-ohm impedance and MMCX connectors, it pairs easily with most sources and allows for cable swapping.

  • Pro:Very lightweight at 6g per ear
  • Pro:Durable aluminum and sapphire-glass build
  • Pro:Single dynamic driver offers coherent sound
  • Con:No noise cancellation for noisy environments
  • Con:Wired-only design limits portability convenience
  • Con:LCP diaphragm may require burn-in for optimal sound

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

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

Compare something else

Swap either side out, or start again from the picker.

New comparison7Hz EternalLetshuoer S12 Ultra