Short answer: a tie on sound quality. Both are rated 4.5/5 (#84 and #68 of 450 in-ear headphones) at nearly the same price ($53.61 vs $49.99), so choose on features and fit.
What the Kefine Klean does well: Four squig.link measurements give the Klean a preference score of 79.4 with a very smooth 1.32 dB deviation from target. The catch: A 5 dB dip near 9.9 kHz dulls the shimmer of cymbals and strings, and presence sits 1.9 dB below target, softening vocal edges.
The case for the Ooopusx OP24: Its six-driver hybrid scores 80.0 across 11 hobbyist measurements on squig.link, and sub-bass and bass both sit nearly 2 dB above target, giving electronic and hip hop tracks a full, rumbling low end. The tradeoff: A 5.8 dB peak near 8.1 kHz can make cymbals and esses sound splashy on bright recordings.
Buy the Kefine Klean or the Ooopusx OP24 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.
Specifications Side By Side
| Kefine Klean | Ooopusx OP24 | |
|---|---|---|
| Price | $53.61 | $49.99 |
| Ranked | #84 of 450 in In-Ear Headphones | #68 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 79 (median of 4 squig.link measurements, calibrated to AutoEQ) | 80 (median of 12 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 1.32 dB standard deviation | 1.42 dB standard deviation |
| Tonal Tilt | -0.39 (negative is warmer, positive brighter) | -0.32 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.0 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+1.3 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Dynamic | Hybrid (2 dynamic + 4 balanced armature) |
| Drivers | 1 x 10mm dynamic | 2 x dynamic + 4 x balanced armature |
| Impedance | 32 ohms | 15 ohms (27 ohms in mode 2) |
| Sensitivity | 107 dB | 127 dB/Vrms |
| Weight | 0 lbs (10 g) | - |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) | 10Hz - 40kHz (Manufacturer specified) |
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- ThieAudio Legacy 4 vs Ooopusx OP24
- CCA Rhapsody vs Ooopusx OP24
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- Ooopusx OP24 vs TANGZU Wan’er SG Studio Edition
- CCA Rhapsody vs Kefine Klean
Prices on this page were last checked October 11, 2026 at 4:59 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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The Two Headphones In Full
Kefine Klean: $53.61 Amazon eBay
Pros: Four squig.link measurements give the Klean a preference score of 79.4 with a very smooth 1.32 dB deviation from target. Sub-bass 1.3 dB and bass 2.1 dB above target give it a warm, rich low end that suits bassy tastes, while mids stay close to neutral. At 32 ohms and 107 dB it plays well from a phone, and it weighs 10 g.
Cons: A 5 dB dip near 9.9 kHz dulls the shimmer of cymbals and strings, and presence sits 1.9 dB below target, softening vocal edges. It costs more than the equally rated KZ Duonic and Sivga SM100.
Full Kefine Klean review and specifications →
| Released | Oct 2024 (2 years ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 1.32 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 10mm dynamic |
| Form Factor | In-ear |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) |
| Harman Preference Score | 79 (median of 4 squig.link measurements, calibrated to AutoEQ) |
| Impedance | 32 ohms |
| Sensitivity | 107 dB |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.0 dB at 30 Hz) |
| Tonal Tilt | -0.39 (negative is warmer, positive brighter) |
| Weight | 0 lbs (10 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Ooopusx OP24: $49.99 Amazon eBay
Pros: Its six-driver hybrid scores 80.0 across 11 hobbyist measurements on squig.link, and sub-bass and bass both sit nearly 2 dB above target, giving electronic and hip hop tracks a full, rumbling low end. Treble from 6 to 10 kHz is lifted about 1.9 dB for crisp detail, a lively v-shaped balance. A second impedance mode (15 or 27 ohms) gives a tuning option, and 127 dB/Vrms sensitivity makes it easy to drive.
Cons: A 5.8 dB peak near 8.1 kHz can make cymbals and esses sound splashy on bright recordings. The 4.7 dB dip that follows near 10.2 kHz makes the top end uneven rather than smoothly extended.
Full Ooopusx OP24 review and specifications →
| Released | Aug 2025 (1 year ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 1.42 dB standard deviation |
| Driver Type | Hybrid (2 dynamic + 4 balanced armature) |
| Drivers | 2 x dynamic + 4 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 10Hz - 40kHz (Manufacturer specified) |
| Harman Preference Score | 80 (median of 12 squig.link measurements, calibrated to AutoEQ) |
| Impedance | 15 ohms (27 ohms in mode 2) |
| Sensitivity | 127 dB/Vrms |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.3 dB at 30 Hz) |
| Tonal Tilt | -0.32 (negative is warmer, positive brighter) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons