Short answer: a tie on sound quality. Both are rated 4.3/5 (#184 and #218 of 1291 in-ear headphones) at nearly the same price ($55.99 vs $51.99), so choose on features and fit.
Why pick the KZ ZEX Pro: The median of 20 hobbyist measurements gives it a very good Harman preference score of 78 with a 1.60 dB spread. The catch: Presence sits about 3.2 dB low with a 6.6 dB dip near 11.9 kHz, so vocals and instruments lose some bite.
The case for the TKZK Ouranos: The median of 6 hobbyist measurements gives it a very good Harman preference score of 77 with a 1.71 dB spread, and its mids sit within about 0.5 dB of target, so vocals and instruments sound natural. The tradeoff: A 4.2 dB peak near 11.9 kHz can make cymbals and sibilance sound sharp.
Buy the KZ ZEX Pro or the TKZK Ouranos on features: they are rated the same for sound quality at close to the same price.
Still deciding? The full Headphones rankings cover every ranked option.
The median of 20 hobbyist measurements gives it a very good Harman preference score of 78 with a 1.60 dB spread.
Amazon $55.99 eBay
The median of 6 hobbyist measurements gives it a very good Harman preference score of 77 with a 1.71 dB spread, and its mids sit within about 0.5 dB of target, so vocals and instruments sound natural.
Amazon $51.99 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
| KZ ZEX Pro | TKZK Ouranos | |
|---|---|---|
| Price | $55.99 | $51.99 |
| Ranked | #184 of 1291 in In-Ear Headphones | #218 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 78 (median of 20 squig.link measurements, calibrated to AutoEQ) | 77 (median of 6 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 1.60 dB standard deviation | 1.71 dB standard deviation |
| Tonal Tilt | -0.27 (negative is warmer, positive brighter) | -0.28 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.6 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-1.7 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (1 dynamic + 1 balanced armature + 1 electrostatic) | Dynamic |
| Drivers | 1 x 10mm dynamic + 1 x balanced armature + 1 x electrostatic | 1 x 10mm dynamic |
| Impedance | 25 ohms | 320 ohms |
| Sensitivity | 104 dB | 110 dB |
| Frequency Response | 20Hz - 40kHz (Manufacturer specified) | 10Hz - 20kHz (Manufacturer specified) |
| Built-in Microphone | - | No |
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 KZ ZEX Pro from achoreviews, aftersound, ankramutt, bassyalexander, boizoff, dchpgall, dentreviews, eplv, filk, flare, hbb, ianfann, jacstone, loomynarty, lown-fi, precog, recode, rg, tgx78 and vortexreviews; the TKZK Ouranos from achoreviews, cqtek, fahryst, ianfann, pw and timmyv, all via squig.link.
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