Short answer: the Fearless Audio S8F. It ranks #353 of 450 in-ear headphones by sound quality, rated 3.5/5, at $489. The Fearless Audio S6Rui ranks #372, rated 3.3/5, at $389, $100 cheaper, a saving that is not big enough to make up the sound-quality gap.
Why pick the Fearless Audio S8F: Crinacle’s measurement gives it a preference score of 68, a moderate match to the response most listeners prefer. The tradeoff: A 2.5 dB standard deviation from target points to an uneven response.
Why pick the Fearless Audio S6Rui: Six balanced armature drivers per side earn a preference score of 65 in crinacle’s measurement, a serviceable match to the Harman target. The catch: A 2.7 dB standard deviation from target points to an uneven response that benefits from some EQ.
Buy the Fearless Audio S8F. It is rated higher for sound quality, and the $100 saving on the Fearless Audio S6Rui is not enough to make up the difference.
Still deciding? The full Headphones rankings cover every ranked option.
Specifications Side By Side
| Fearless Audio S8F | Fearless Audio S6Rui | |
|---|---|---|
| Price | $489.00 | $389.00 |
| Ranked | #353 of 450 in In-Ear Headphones | #372 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 68 (measured by crinacle, via AutoEQ) | 65 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 2.47 dB standard deviation | 2.70 dB standard deviation |
| Tonal Tilt | -0.40 (negative is warmer, positive brighter) | -0.55 (negative is warmer, positive brighter) |
| Connection | Wired | Wired |
| Driver Type | Balanced armature | Balanced armature |
| Drivers | 8 x balanced armature | 6 x balanced armature |
| Impedance | 26 ohms | 20 ohms |
| Sensitivity | 113 dB/mW | 113 dB |
| Frequency Response | 15Hz - 20kHz (Manufacturer specified) | 15Hz - 20kHz (Manufacturer specified) |
| Built-in Microphone | No | No |
Related Headphone Comparisons
How Fearless Audio S8F compares with other leading options:
- FiiO FD5 vs Fearless Audio S8F
- iBasso IT04 vs Fearless Audio S8F
- Kinera Norn vs Fearless Audio S8F
- Fearless Audio S6Rui vs Cayin Fantasy
- Fearless Audio S6Rui vs FiiO FH7S
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
Fearless Audio S8F: $489.00 Linsoul eBay
Pros: Crinacle’s measurement gives it a preference score of 68, a moderate match to the response most listeners prefer. Eight balanced armatures at 26 ohms and 113 dB/mW sensitivity make it easy to drive from a phone.
Cons: A 2.5 dB standard deviation from target points to an uneven response. The iBasso IT04 is rated higher at a similar price.
Full Fearless Audio S8F review and specifications →
| Back | Closed |
|---|---|
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 2.47 dB standard deviation |
| Driver Type | Balanced armature |
| Drivers | 8 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 15Hz - 20kHz (Manufacturer specified) |
| Harman Preference Score | 68 (measured by crinacle, via AutoEQ) |
| Impedance | 26 ohms |
| Sensitivity | 113 dB/mW |
| Tonal Tilt | -0.40 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -3.1 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 | +2.1 dB | 0.70 |
| Peak | 177 Hz | -4.2 dB | 0.41 |
| Peak | 864 Hz | +3.9 dB | 0.91 |
| Peak | 2,553 Hz | +2.6 dB | 2.45 |
| Peak | 181 Hz | -0.2 dB | 2.11 |
| High shelf | 10,000 Hz | +0.4 dB | 0.70 |
| Peak | 9,175 Hz | +2.2 dB | 1.87 |
| Peak | 4,346 Hz | -1.2 dB | 2.77 |
| Peak | 5,451 Hz | +1.7 dB | 6.00 |
| Peak | 39 Hz | -0.2 dB | 1.83 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Fearless Audio S6Rui: $389.00 Linsoul eBay
Pros: Six balanced armature drivers per side earn a preference score of 65 in crinacle’s measurement, a serviceable match to the Harman target. A 20 ohm impedance and 113 dB sensitivity let it reach loud levels straight from a phone or dongle. It earns the same rating as the OpenAudio Mercury for noticeably less money.
Cons: A 2.7 dB standard deviation from target points to an uneven response that benefits from some EQ. The Fearless Audio S8F from the same maker rates higher for a modest step up in price.
Full Fearless Audio S6Rui review and specifications →
| Back | Closed |
|---|---|
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 2.70 dB standard deviation |
| Driver Type | Balanced armature |
| Drivers | 6 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 15Hz - 20kHz (Manufacturer specified) |
| Harman Preference Score | 65 (measured by crinacle, via AutoEQ) |
| Impedance | 20 ohms |
| Sensitivity | 113 dB |
| Tonal Tilt | -0.55 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -6.5 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 | +1.8 dB | 0.70 |
| Peak | 166 Hz | -4.4 dB | 0.48 |
| Peak | 851 Hz | +3.4 dB | 1.06 |
| Peak | 2,720 Hz | +2.4 dB | 3.00 |
| Peak | 1,770 Hz | -1.3 dB | 2.18 |
| High shelf | 10,000 Hz | +6.5 dB | 0.70 |
| Peak | 5,650 Hz | +6.2 dB | 2.53 |
| Peak | 4,718 Hz | -4.5 dB | 3.03 |
| Peak | 8,599 Hz | +3.3 dB | 2.26 |
| Peak | 3,846 Hz | -1.8 dB | 6.00 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons