Short answer: the ThieAudio Monarch MKIII. It ranks #1 of 749 in-ear headphones by sound quality (rated 4.9/5) at $999 and is still sold new; the ThieAudio Monarch ranks #72 (rated 4.6/5) and is discontinued, so it is only an option used. The ThieAudio Monarch’s replacement, the ThieAudio Monarch MKIV, is rated 4.4/5 at $1,149.
Why pick the ThieAudio Monarch: Measured response gives it an excellent Harman preference score of 81 with a 1.59 dB spread, and its mids sit within about 0.5 dB of target, so vocals and instruments sound natural. The tradeoff: Discontinued, so it is mainly found used.
The ThieAudio Monarch MKIII is the better-sounding option. A preference score of 91 in HypetheSonics’ measurement, with an exceptionally smooth 0.77 dB standard deviation from target. The catch: The air band from 10 to 16 kHz sits about 5.7 dB above target with a 4.4 dB peak near 11.9 kHz, which can add a hint of glare on bright or sibilant recordings.
Buy the ThieAudio Monarch MKIII. It is rated higher for sound quality and still sold new, while the ThieAudio Monarch is discontinued.
Looking for alternatives? See the complete Headphones rankings.
Specifications Side By Side
| ThieAudio Monarch | ThieAudio Monarch MKIII | |
|---|---|---|
| Price | Discontinued | $999.00 |
| Ranked | #72 of 749 in In-Ear Headphones | #1 of 749 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Connection | Wired | Wired |
| Driver Type | Tribrid | Hybrid (2 dynamic + 6 balanced armature + 2 electrostatic) |
| Drivers | 1 x 10mm dynamic + 6 x balanced armature + 2 x electrostatic | 2 x 10mm dynamic + 6 x balanced armature + 2 x electrostatic |
| Impedance | 26 ohms | 18 ohms |
| Harman Preference Score | 81 (measured by oratory1990, via AutoEQ) | 91 (measured by HypetheSonics, via AutoEQ) |
| Deviation From Target | 1.59 dB standard deviation | 0.77 dB standard deviation |
| Tonal Tilt | -0.39 (negative is warmer, positive brighter) | -0.11 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+3.0 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-0.8 dB at 30 Hz) |
| Back | - | Closed |
| Sensitivity | - | 99 dB @ 1kHz |
| Frequency Response | - | 20Hz - 80kHz (Manufacturer specified) |
| Built-in Microphone | - | No |
Related Headphone Comparisons
More worthwhile head-to-heads for ThieAudio Monarch MKIII:
- Moondrop Dark Saber vs ThieAudio Monarch MKIII
- ThieAudio Monarch MKIII vs Simgot EW100P
- ThieAudio Monarch MKII vs ThieAudio Monarch MKIII
- ThieAudio Monarch MKIII vs Symphonium Audio Helios
- ThieAudio Monarch MKIII vs ThieAudio Monarch MKIV
Prices on this page were last checked October 12, 2026 at 4:13 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 Discontinued eBay
Newer model: the ThieAudio Monarch MKIV, ranked lower, rated 4.4/5, released Jul 2025. See every ThieAudio Monarch generation.
Pros: Measured response gives it an excellent Harman preference score of 81 with a 1.59 dB spread, and its mids sit within about 0.5 dB of target, so vocals and instruments sound natural. Bass sits close to target and holds down to 20 Hz, so low end sounds full without bloat. It uses 1 x 10mm dynamic + 6 x balanced armature + 2 x electrostatic with an easy 26 ohm load.
Cons: Discontinued, so it is mainly found used. A 4.5 dB peak near 7.9 kHz can make cymbals and sibilance sound sharp.
Full ThieAudio Monarch review and specifications →
| Released | 2020 (6 years ago) |
|---|---|
| Connection | Wired |
| Deviation From Target | 1.59 dB standard deviation |
| Driver Type | Tribrid |
| Drivers | 1 x 10mm dynamic + 6 x balanced armature + 2 x electrostatic |
| Form Factor | In-ear |
| Harman Preference Score | 81 (measured by oratory1990, via AutoEQ) |
| Impedance | 26 ohms |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+3.0 dB at 30 Hz) |
| Tonal Tilt | -0.39 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -2.0 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 | -5.4 dB | 0.70 |
| Peak | 75 Hz | +4.0 dB | 0.72 |
| Peak | 8,151 Hz | -2.4 dB | 2.01 |
| Peak | 1,416 Hz | -1.4 dB | 1.83 |
| Peak | 771 Hz | +1.0 dB | 1.40 |
| High shelf | 10,000 Hz | -0.9 dB | 0.70 |
| Peak | 3,303 Hz | +1.8 dB | 2.97 |
| Peak | 4,753 Hz | +2.5 dB | 5.73 |
| Peak | 5,521 Hz | -2.3 dB | 6.00 |
| Peak | 2,110 Hz | -0.5 dB | 2.48 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
ThieAudio Monarch MKIII: $999.00 Linsoul $999.00 eBay
Newer model: the ThieAudio Monarch MKIV, ranked lower, rated 4.4/5, released Jul 2025.
Older models: the ThieAudio Monarch MKII (ranked lower, rated 4.6/5) and the ThieAudio Monarch (ranked lower, rated 4.6/5). See every ThieAudio Monarch generation.
Pros: A preference score of 91 in HypetheSonics’ measurement, with an exceptionally smooth 0.77 dB standard deviation from target. Everything from 20 Hz to 10 kHz stays within about 1.1 dB of target, so bass, vocals and treble all sound balanced and true. It rates above the pricier Symphonium Audio Helios and well above the SoftEars RSV.
Cons: The air band from 10 to 16 kHz sits about 5.7 dB above target with a 4.4 dB peak near 11.9 kHz, which can add a hint of glare on bright or sibilant recordings. It is a wired in-ear with no built-in microphone, so it is not suited to calls on the go.
Full ThieAudio Monarch MKIII review and specifications →
| Released | 2023 (3 years ago) |
|---|---|
| Back | Closed |
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 0.77 dB standard deviation |
| Driver Type | Hybrid (2 dynamic + 6 balanced armature + 2 electrostatic) |
| Drivers | 2 x 10mm dynamic + 6 x balanced armature + 2 x electrostatic |
| Form Factor | In-ear |
| Frequency Response | 20Hz - 80kHz (Manufacturer specified) |
| Harman Preference Score | 91 (measured by HypetheSonics, via AutoEQ) |
| Impedance | 18 ohms |
| Sensitivity | 99 dB @ 1kHz |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.8 dB at 30 Hz) |
| Tonal Tilt | -0.11 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -1.0 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 | -0.1 dB | 0.70 |
| Peak | 742 Hz | +1.1 dB | 1.13 |
| Peak | 130 Hz | -1.1 dB | 1.51 |
| Peak | 1,584 Hz | -0.6 dB | 1.19 |
| Peak | 3,281 Hz | +0.9 dB | 4.08 |
| High shelf | 10,000 Hz | -7.9 dB | 0.70 |
| Peak | 8,077 Hz | +1.8 dB | 1.48 |
| Peak | 5,639 Hz | -1.4 dB | 6.00 |
| Peak | 9,669 Hz | +1.1 dB | 4.55 |
| Peak | 60 Hz | +0.1 dB | 2.11 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons