Short answer: the CCA CSN. It ranks #819 of 1369 in-ear headphones by sound quality, rated 3.5/5, at $25.99; the CCA Hydro ranks #960, rated 3.3/5, at $24.99. With prices this close, go by the sound-quality ranking rather than the cost.
What the CCA CSN does well: Across six hobbyist measurements on squig.link, bass runs about 2 dB above target with sub-bass only 1.4 dB short at 30 Hz, giving a warm, full low end that suits pop and electronic music. The catch: A 6.9 dB dip near 3.4 kHz sets voices back, while a 5.5 dB peak at 8.1 kHz can make cymbals and sibilants splashy, a V-shaped balance that will not suit neutral tastes.
The case for the CCA Hydro: About 3 dB more bass than the Harman target below 150 Hz, for listeners who want a fuller low end. The tradeoff: An uneven response, 2.5 dB standard deviation from target.
Buy the CCA CSN. It is rated higher for sound quality, and the $1 you would save on the CCA Hydro does not close the gap.
Looking for alternatives? See the complete Headphones rankings.
Across six hobbyist measurements on squig.link, bass runs about 2 dB above target with sub-bass only 1.4 dB short at 30 Hz, giving a warm, full low end that suits pop and electronic music.
Amazon $25.99 eBay
About 3 dB more bass than the Harman target below 150 Hz, for listeners who want a fuller low end.
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Specifications Side By Side
| CCA CSN | CCA Hydro | |
|---|---|---|
| Price | $25.99 | 24.99 |
| Ranked | #819 of 1369 in In-Ear Headphones | #960 of 1369 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Harman Preference Score | 67 (measured by crinacle, via AutoEQ) | 65 (median of 4 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.64 dB standard deviation | 2.54 dB standard deviation |
| Tonal Tilt | -0.46 (negative is warmer, positive brighter) | -0.37 (negative is warmer, positive brighter) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (1 dynamic + 1 balanced armature) | Hybrid |
| Drivers | 1 x 10mm dynamic + 1 x balanced armature | 10 drivers (2 dynamic drivers + 8 balanced armatures) |
| Impedance | 22.5 ohms | 15-20 ohms |
| Sensitivity | 112 dB/mW | 102 dB |
| Frequency Response | 20Hz - 40kHz | 20Hz - 40kHz |
| Back | Closed | Closed |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-1.4 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+0.3 dB at 30 Hz) |
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 CCA CSN from aftersound, bedrock, melatonin, precog, pw and vortexreviews; the CCA Hydro from audioamigo, obodio, pw and superreview, all via squig.link.
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