Short answer: the Cayin Fantasy. Both are rated 3.0/5 for sound quality (#395 and #390 of 450 in-ear headphones), and the Cayin Fantasy costs $399 against $459 for the HiBy Crystal 6, so with nothing between them on sound quality, price settles it.
Why pick the Cayin Fantasy: Its single 10.3mm dynamic driver at 37 ohms and 108 dB runs from a phone without strain. Watch for: Crinacle’s measurement gives it a preference score of only 61.0, and squig.link hobbyist measurements show treble about 5.5 dB hot with a 12.4 dB peak near 11.2 kHz, so cymbals and sibilance can turn harsh.
What the HiBy Crystal 6 does well: A lively V-shaped tuning with about 3.7 dB of extra bass and a treble lift of 5 to 6 dB above 6 kHz, which gives drums punch and cymbals plenty of sparkle. The tradeoff: Squig.link measurements show a 9.9 dB peak near 7.9 kHz, so sibilance and hi-hats can turn sharp and fatiguing at higher volumes.
Buy the Cayin Fantasy. Both are rated the same for sound quality, and it costs $60 less than the HiBy Crystal 6.
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Specifications Side By Side
| Cayin Fantasy | HiBy Crystal 6 | |
|---|---|---|
| Price | $399.00 | $459.00 |
| Ranked | #395 of 450 in In-Ear Headphones | #390 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 61 (measured by crinacle, via AutoEQ) | 62 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 3.04 dB standard deviation | 3.17 dB standard deviation |
| Tonal Tilt | +1.05 (negative is warmer, positive brighter) | +0.21 (negative is warmer, positive brighter) |
| Connection | Wired | Wired |
| Driver Type | Dynamic | Balanced armature |
| Drivers | 1 x 10.3mm dynamic | 6 x balanced armature |
| Impedance | 37 ohms | 14 ohms |
| Sensitivity | 108 dB | 107 dB/mW |
| Frequency Response | 20Hz - 40kHz (Manufacturer specified) | 5Hz - 60kHz (Manufacturer specified) |
| Built-in Microphone | No | No |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-4.7 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-5.0 dB at 30 Hz) |
Related Headphone Comparisons
More top alternatives to HiBy Crystal 6:
- HiBy Crystal 6 vs Yanyin Mahina
- HiBy Crystal 6 vs Shanling ME700
- HiBy Crystal 6 vs FiiO FA9
- Cayin Fantasy vs Jabra Evolve 75e
- Fearless Audio S6Rui vs Cayin Fantasy
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
Cayin Fantasy: $399.00 HiFiGo eBay
Pros: Its single 10.3mm dynamic driver at 37 ohms and 108 dB runs from a phone without strain. Listeners who want a bright, detail-forward presentation will find treble well above target, and it costs less than the equally rated Fatfreq Reference Pro SE.
Cons: Crinacle’s measurement gives it a preference score of only 61.0, and squig.link hobbyist measurements show treble about 5.5 dB hot with a 12.4 dB peak near 11.2 kHz, so cymbals and sibilance can turn harsh. Sub-bass sits about 3.8 dB below target, leaving the low end thin.
Full Cayin Fantasy review and specifications →
| Back | Closed |
|---|---|
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 3.04 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 10.3mm dynamic |
| Form Factor | In-ear |
| Frequency Response | 20Hz - 40kHz (Manufacturer specified) |
| Harman Preference Score | 61 (measured by crinacle, via AutoEQ) |
| Impedance | 37 ohms |
| Sensitivity | 108 dB |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-4.7 dB at 30 Hz) |
| Tonal Tilt | +1.05 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -6.4 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +7.7 dB | 0.70 |
| Peak | 767 Hz | +3.8 dB | 0.87 |
| Peak | 77 Hz | -3.3 dB | 0.34 |
| Peak | 5,276 Hz | -7.3 dB | 5.21 |
| Peak | 2,652 Hz | -3.2 dB | 3.85 |
| High shelf | 10,000 Hz | -2.9 dB | 0.70 |
| Peak | 3,867 Hz | +1.2 dB | 4.18 |
| Peak | 7,406 Hz | -1.6 dB | 6.00 |
| Peak | 6,488 Hz | +1.3 dB | 6.00 |
| Peak | 1,421 Hz | -0.3 dB | 3.75 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
HiBy Crystal 6: $459.00 HiFiGo eBay
Pros: A lively V-shaped tuning with about 3.7 dB of extra bass and a treble lift of 5 to 6 dB above 6 kHz, which gives drums punch and cymbals plenty of sparkle. Sub-bass stays within 6 dB of target down to 20 Hz. Six balanced armatures at 14 ohms and 107 dB/mW run fine from a phone. It matches the rating of the Shanling ME700 for less money.
Cons: Squig.link measurements show a 9.9 dB peak near 7.9 kHz, so sibilance and hi-hats can turn sharp and fatiguing at higher volumes. A 3.7 dB lift from 200 Hz to 1 kHz thickens male vocals and lower instruments. The Etymotic ER4XR earns the same rating for considerably less.
Full HiBy Crystal 6 review and specifications →
| Released | Mar 2021 (5 years ago) |
|---|---|
| Back | Closed |
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 3.17 dB standard deviation |
| Driver Type | Balanced armature |
| Drivers | 6 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 5Hz - 60kHz (Manufacturer specified) |
| Harman Preference Score | 62 (measured by crinacle, via AutoEQ) |
| Impedance | 14 ohms |
| Sensitivity | 107 dB/mW |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-5.0 dB at 30 Hz) |
| Tonal Tilt | +0.21 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -4.5 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +5.0 dB | 0.70 |
| Peak | 173 Hz | -3.8 dB | 0.30 |
| Peak | 1,805 Hz | +2.9 dB | 2.77 |
| Peak | 6,231 Hz | -6.6 dB | 5.99 |
| Peak | 945 Hz | +4.5 dB | 0.93 |
| High shelf | 10,000 Hz | +0.4 dB | 0.70 |
| Peak | 4,649 Hz | +2.8 dB | 5.98 |
| Peak | 2,604 Hz | -1.7 dB | 6.00 |
| Peak | 5,438 Hz | -1.5 dB | 6.00 |
| Peak | 36 Hz | -0.2 dB | 1.94 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons