Short answer: the Lime Ears Terra. It ranks #84 of 1291 in-ear headphones by sound quality, rated 4.6/5, at $1,199. The ThieAudio Monarch MKIV ranks #138, rated 4.4/5, at $1,149, $50 cheaper, a saving that is not big enough to make up the sound-quality gap.
The case for the Lime Ears Terra: Fourteen hobbyist measurements on squig.link put its preference score at 80.8 with a smooth 1.26 dB deviation. The tradeoff: It rates below the Moondrop Dark Saber and ThieAudio Monarch MKIII, both of which cost less.
The case for the ThieAudio Monarch MKIV: Across 14 squig.link measurements it posts a preference score of 79.0 with a very smooth 1.31 dB spread. The catch: 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 Lime Ears Terra. It is rated higher for sound quality, and the $50 saving on the ThieAudio Monarch MKIV is not enough to make up the difference.
Still deciding? The full Headphones rankings cover every ranked option.
Fourteen hobbyist measurements on squig.link put its preference score at 80.8 with a smooth 1.26 dB deviation.
Lime Ears $1,199.00 eBay
Across 14 squig.link measurements it posts a preference score of 79.0 with a very smooth 1.31 dB spread.
Linsoul $1,149.00 eBayPrices on this page were last checked October 16, 2026 at 5:46 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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Specifications Side By Side
| Lime Ears Terra | ThieAudio Monarch MKIV | |
|---|---|---|
| Price | $1,199.00 | $1,149.00 |
| Ranked | #84 of 1291 in In-Ear Headphones | #138 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 81 (median of 14 squig.link measurements, calibrated to AutoEQ) | 79 (median of 14 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 1.26 dB standard deviation | 1.31 dB standard deviation |
| Tonal Tilt | -0.37 (negative is warmer, positive brighter) | -0.43 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.0 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-0.2 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (1 dynamic + 5 balanced armature) | Hybrid (2 dynamic + 6 balanced armature + 2 electrostatic) |
| Drivers | 1 x 7mm dynamic + 5 x balanced armature | 2 x 8mm dynamic + 6 x balanced armature + 2 x electrostatic |
| Sensitivity | - | 100 dB |
| Frequency Response | - | 10Hz - 44kHz (Manufacturer specified) |
| Built-in Microphone | - | No |
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 Lime Ears Terra from aden, animagus, atechreviews, audioamigo, ducbloke, hbb, jaytiss, koi, melatonin, practiphile, precog, pw, recode, silicagel, superreview, theaudiostore and vsg; the ThieAudio Monarch MKIV from bassaudio, boizoff, breampike, csi-zone, eliseaudio, hbb, iemocean, jaytiss, joycesreview, lown-fi, pw, soundignity, superreview and tonedeafmonk, all via squig.link.
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