Short answer: the ThieAudio Monarch MKIV. It ranks #105 of 450 in-ear headphones by sound quality, rated 4.4/5, at $1,149. The Letshuoer Mystic 8 ranks #169, rated 4.3/5, at $989, $160 cheaper, which does not close the gap in sound quality.
What the ThieAudio Monarch MKIV does well: Across 14 squig.link measurements it posts a preference score of 79.0 with a very smooth 1.31 dB spread. Watch for: Presence sits 2.7 dB below target with a 3.7 dB dip near 6.4 kHz, so vocals and strings lose some immediacy.
Buy the ThieAudio Monarch MKIV. It is rated higher for sound quality, and the $160 saving on the Letshuoer Mystic 8 is not enough to make up the difference.
Looking for alternatives? See the complete Headphones rankings.
Specifications Side By Side
| ThieAudio Monarch MKIV | Letshuoer Mystic 8 | |
|---|---|---|
| Price | $1,149.00 | $989.00 |
| Ranked | #105 of 450 in In-Ear Headphones | #169 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 79 (median of 14 squig.link measurements, calibrated to AutoEQ) | 77 (median of 21 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 1.31 dB standard deviation | 1.66 dB standard deviation |
| Tonal Tilt | -0.43 (negative is warmer, positive brighter) | +0.10 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.2 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-2.9 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (2 dynamic + 6 balanced armature + 2 electrostatic) | Balanced armature |
| Drivers | 2 x 8mm dynamic + 6 x balanced armature + 2 x electrostatic | 8 x balanced armature |
| Sensitivity | 100 dB | 107 dB |
| Frequency Response | 10Hz - 44kHz (Manufacturer specified) | 20Hz - 40kHz (Manufacturer specified) |
| Built-in Microphone | No | - |
| Impedance | - | 18 ohms |
Related Headphone Comparisons
More top alternatives to ThieAudio Monarch MKIV:
- ThieAudio Monarch MKIII vs ThieAudio Monarch MKIV
- ThieAudio Monarch MKII vs ThieAudio Monarch MKIV
- Symphonium Audio Helios vs ThieAudio Monarch MKIV
- ThieAudio Monarch MKIV vs DUNU Glacier
- Symphonium Audio Helios vs Letshuoer Mystic 8
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
ThieAudio Monarch MKIV: $1,149.00 Linsoul eBay
Pros: Across 14 squig.link measurements it posts a preference score of 79.0 with a very smooth 1.31 dB spread. Sub-bass and bass sit within half a dB of target, so the dual 8 mm dynamic drivers give clean, accurate low end, and a 5 dB air lift near 12 kHz from the electrostatic tweeters adds shimmer and space. It rates above the SoftEars RSV.
Cons: Presence sits 2.7 dB below target with a 3.7 dB dip near 6.4 kHz, so vocals and strings lose some immediacy. The Moondrop Dark Saber rates well above it for less money, and the Symphonium Audio Helios rates higher at a similar price.
Full ThieAudio Monarch MKIV review and specifications →
| Released | Jul 2025 (1 year ago) |
|---|---|
| Back | Closed |
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 1.31 dB standard deviation |
| Driver Type | Hybrid (2 dynamic + 6 balanced armature + 2 electrostatic) |
| Drivers | 2 x 8mm dynamic + 6 x balanced armature + 2 x electrostatic |
| Form Factor | In-ear |
| Frequency Response | 10Hz - 44kHz (Manufacturer specified) |
| Harman Preference Score | 79 (median of 14 squig.link measurements, calibrated to AutoEQ) |
| Sensitivity | 100 dB |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.2 dB at 30 Hz) |
| Tonal Tilt | -0.43 (negative is warmer, positive brighter) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Letshuoer Mystic 8: $989.00 Linsoul eBay
Full Letshuoer Mystic 8 review and specifications →
| Released | Feb 2025 (1 year ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 1.66 dB standard deviation |
| Driver Type | Balanced armature |
| Drivers | 8 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 20Hz - 40kHz (Manufacturer specified) |
| Harman Preference Score | 77 (median of 21 squig.link measurements, calibrated to AutoEQ) |
| Impedance | 18 ohms |
| Sensitivity | 107 dB |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-2.9 dB at 30 Hz) |
| Tonal Tilt | +0.10 (negative is warmer, positive brighter) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons