Short answer: the Letshuoer S12 Ultra. It ranks #707 of 1291 in-ear headphones by sound quality, rated 3.6/5, at $152.10; the QoA Gimlet ranks #834, rated 3.5/5, and costs $154.04, so there is not much of a tradeoff to weigh.
Why pick the Letshuoer S12 Ultra: The median of 12 hobbyist measurements gives it a solid Harman preference score of 69 with a 2.18 dB spread, and its mids sit within about 0.5 dB of target, so vocals and instruments sound natural. The tradeoff: Presence sits about 4 dB low with a 6 dB dip near 3.4 kHz, so vocals and instruments lose some bite.
Why pick the QoA Gimlet: A single dynamic IEM with a 10mm LCP diaphragm. The tradeoff: A 2.41 dB spread from the target shows peaks and dips that better tuned sets avoid.
Buy the Letshuoer S12 Ultra. It is rated higher for sound quality than the QoA Gimlet and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Looking for alternatives? See the complete Headphones rankings.
The median of 12 hobbyist measurements gives it a solid Harman preference score of 69 with a 2.18 dB spread, and its mids sit within about 0.5 dB of target, so vocals and instruments sound natural.
Amazon $152.10 eBay
A single dynamic IEM with a 10mm LCP diaphragm.
Amazon $154.04 eBayPrices on this page were last checked October 16, 2026 at 5:46 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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Specifications Side By Side
| Letshuoer S12 Ultra | QoA Gimlet | |
|---|---|---|
| Price | $152.10 | $154.04 |
| Ranked | #707 of 1291 in In-Ear Headphones | #834 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Connection | Wired | Wired |
| Driver Type | Planar | Dynamic |
| Drivers | 1 x 14.8mm planar magnetic | 1 x 10mm dynamic (LCP) |
| Impedance | 16 ohms | 32 ohms |
| Frequency Response | 20Hz - 40kHz (Manufacturer specified) | - |
| Harman Preference Score | 69 (median of 12 squig.link measurements, calibrated to AutoEQ) | 67 (median of 7 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.18 dB standard deviation | 2.41 dB standard deviation |
| Tonal Tilt | -0.68 (negative is warmer, positive brighter) | -0.63 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.1 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-0.6 dB at 30 Hz) |
| Sensitivity | - | 108 dB |
Frequency Response Compared
Both headphones’ measurements overlaid on the Harman target. Above the target sounds louder in that range, below it quieter. Each curve is the median of several independent measurements, shifted so its 500 Hz to 2 kHz average sits at 0 dB, so only the tuning is compared.
Measurement data: the Letshuoer S12 Ultra from aden, atechreviews, audioamigo, cqtek, eplv, flare, hbb, jaytiss, pw, soundignity, superreview and tonedeafmonk; the QoA Gimlet from achoreviews, aftersound, arn, fahryst, lown-fi, practiphile and pw, all via squig.link.
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