Short answer: a tie on sound quality. Both are rated 4.1/5 (#327 and #345 of 1291 in-ear headphones) at nearly the same price ($54.99 vs $53.19), so choose on features and fit.
What the KBEAR KB03 does well: The median of 6 hobbyist measurements gives it a very good Harman preference score of 75 with a 1.77 dB spread, and its mids sit within about 0.6 dB of target, so vocals and instruments sound natural. Watch for: A 4.6 dB peak near 8.2 kHz can make cymbals and sibilance sound sharp.
What the KZ ZS10 Pro X does well: The median of 10 hobbyist measurements gives it a very good Harman preference score of 75 with a 1.86 dB spread, and its mids sit within about 0.9 dB of target, so vocals and instruments sound natural. Watch for: A 6.4 dB peak near 10.6 kHz can make cymbals and sibilance sound sharp.
Buy the KBEAR KB03 or the KZ ZS10 Pro X on features: they are rated the same for sound quality at close to the same price.
Want more options? Browse the full Headphones rankings.
The median of 6 hobbyist measurements gives it a very good Harman preference score of 75 with a 1.77 dB spread, and its mids sit within about 0.6 dB of target, so vocals and instruments sound natural.
Amazon $54.99 eBay
The median of 10 hobbyist measurements gives it a very good Harman preference score of 75 with a 1.86 dB spread, and its mids sit within about 0.9 dB of target, so vocals and instruments sound natural.
Amazon $53.19 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.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| KBEAR KB03 | KZ ZS10 Pro X | |
|---|---|---|
| Price | $54.99 | $53.19 |
| Ranked | #327 of 1291 in In-Ear Headphones | #345 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 75 (median of 6 squig.link measurements, calibrated to AutoEQ) | 75 (median of 10 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 1.77 dB standard deviation | 1.86 dB standard deviation |
| Tonal Tilt | -0.51 (negative is warmer, positive brighter) | -0.33 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.3 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+0.7 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (1 dynamic + 1 balanced armature + 1 bone conduction) | Hybrid |
| Drivers | 1 x 10mm dynamic + 1 x balanced armature + 1 x 10mm bone conduction | 1 x 10mm dynamic + 4 x balanced armature |
| Impedance | 9.4 ohms | 29 ohms |
| Sensitivity | 101 dB/mW | - |
| Frequency Response | - | 20Hz - 40kHz |
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 KBEAR KB03 from audioamigo, ducbloke, eplv, jaytiss, pw and tonedeafmonk; the KZ ZS10 Pro X from ankramutt, flare, hoods, ianfann, iemworld, pw, superreview, theaudiostore, treblewellxtended and vortexreviews, all via squig.link.
Related Headphone Comparisons
How KBEAR KB03 compares with other leading options: