FiiO FD15 vs Letshuoer S12 Ultra: which should you buy?

Specs, scores and condensed review verdicts for the FiiO FD15 vs Letshuoer S12 Ultra, side by side. Where a product has no HearWiki score yet, not enough reviews have been aggregated to rate it.

Wired IEMs

FiiO FD15

Not yet scored

$100

Full review data

Wired IEMs

Score 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.

FiiO FD15
Letshuoer S12 Ultra

HearWiki score

Sound

8.6

Value

8.9

Price (USD)

$100

$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

Letshuoer S12 Ultra (2025) against FiiO FD15 (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.

FD152024
S12 Ultra20251 yr newer

Specifications

FD15S12 Ultra

Type: Wired IEMs; Wired IEMs
Price (USD): $100; $170
HearWiki score: Not scored; 83
Released: 2024; 2025
Availability: Discontinued; Sold new
Driver: 13.8 mm dynamic; 1 planar magnetic
Driver type: dynamic; planar
Driver configuration: -; 1 planar magnetic
Driver size: 13.8 mm; 14.8 mm
Drivers per side: 1; 1
Frequency response: 10 Hz - 40 kHz; -
Impedance: 32 Ω; 16 Ω
Sensitivity: 112 dB/mW; -
Active noise cancelling: No; -
Controls: none; -
Weight: 12 g; -
Detachable cable: Yes; -
USB-C: No; -
Connector: MMCX; -

Specification comparison of FiiO FD15 vs Letshuoer S12 Ultra
Spec	FiiO FD15	Letshuoer S12 Ultra
Type	Wired IEMs	Wired IEMs
Price (USD)	$100	$170
HearWiki score	Not scored	83 / 100 Outstanding
Released	2024	2025
Audio
Driver	13.8 mm dynamic	1 planar magnetic
Driver type	dynamic	planar
Driver configuration	-	1 planar magnetic
Driver size	13.8 mm	14.8 mm
Drivers per side	1	1
Frequency response	10 Hz - 40 kHz	-
Impedance	32 Ω	16 Ω
Sensitivity	112 dB/mW	-
Features
Active noise cancelling	No	-
Controls	none	-
Design
Weight	12 g	-
Detachable cable	Yes	-
USB-C	No	-
Connector	MMCX	-

What reviewers said

FiiO FD15

The FiiO FD15 is a wired, single-dynamic-driver in-ear monitor with a 13.8mm aluminum-magnesium driver, tuned for a wide 10Hz-40kHz response. Its detachable cable uses a hybrid silver and monocrystalline copper construction with an expanded MMCX connector, offering a lightweight, comfortable fit. Priced around $100, it's a straightforward, no-frills option for listeners who prefer a pure analog connection.

Pro:Wide frequency response with detailed highs
Pro:Lightweight design (12g) for all-day comfort
Pro:Detachable MMCX cable for easy replacement

Con:No active noise cancellation
Con:No inline controls or microphone
Con:Requires a wired source with MMCX compatible cable

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

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 comparison FiiO FD15 Letshuoer S12 Ultra