Short answer: the DUNU Zen. It ranks #510 of 1291 in-ear headphones by sound quality, rated 3.9/5, at $699.99; the FiiO FX15 ranks #551, rated 3.8/5, at $699.99. The price gap is small enough that the sound-quality ranking should decide it.
The case for the DUNU Zen: Crinacle’s measurement earns it a preference score of 72, and squig.link measurements show a warm, slightly bass-lifted tuning with bass about 1.6 dB above target that suits warm and bassy tastes. The tradeoff: Air above 10 kHz falls about 8 dB short of target, with an 11 dB hole near 11.9 kHz, so the top end sounds rolled off and lacks shimmer.
What the FiiO FX15 does well: Its hybrid of one 10mm dynamic driver, one balanced armature and four electrostatic tweeters delivers a warm, gently V-shaped sound with a preference score of 72 across seven hobbyist measurements. The tradeoff: A 7.4 dB peak near 8.1 kHz next to a 4.8 dB dip near 6.1 kHz makes cymbals and sibilants uneven, with some edge on bright tracks.
Buy the DUNU Zen. It is rated higher for sound quality than the FiiO FX15 at the same price, so it is the default pick unless a specific strength of the other one matters more to you.
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Crinacle’s measurement earns it a preference score of 72, and squig.link measurements show a warm, slightly bass-lifted tuning with bass about 1.6 dB above target that suits warm and bassy tastes.
Shenzhenaudio $699.99 eBay
Its hybrid of one 10mm dynamic driver, one balanced armature and four electrostatic tweeters delivers a warm, gently V-shaped sound with a preference score of 72 across seven hobbyist measurements.
Amazon $699.99 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
| DUNU Zen | FiiO FX15 | |
|---|---|---|
| Price | $699.99 | $699.99 |
| Ranked | #510 of 1291 in In-Ear Headphones | #551 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 72 (measured by crinacle, via AutoEQ) | 72 (median of 7 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.48 dB standard deviation | 2.15 dB standard deviation |
| Tonal Tilt | +0.21 (negative is warmer, positive brighter) | -0.36 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-1.6 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+0.1 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Dynamic | Hybrid (1 dynamic + 1 balanced armature + 4 electrostatic) |
| Drivers | 1 x dynamic | 1 x 10mm dynamic + 1 x balanced armature + 4 x electrostatic |
| Impedance | 16 ohms | 24 ohms |
| Sensitivity | 112 dB | 103 dB/mW |
| Frequency Response | 5Hz - 40kHz (Manufacturer specified) | 20Hz - 40kHz (Manufacturer specified) |
| Built-in Microphone | No | No |
| Weight | - | 0 lbs (6 g) per earpiece |
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 DUNU Zen from dchpgall, dentreviews, kazi, nymz, precog, rg and superreview; the FiiO FX15 from dchpgall, jaytiss, precog, silicagel, superreview, timmyv and vsg, all via squig.link.
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