Short answer: a tie on sound quality. Both are rated 4.7/5 (#34 and #38 of 450 in-ear headphones) at nearly the same price ($349.99 vs $349.99), so choose on features and fit.
The case for the EPZ K9: In the median of 19 hobbyist measurements on squig.link, the K9 earns a preference score of 82 with a low 1.26 dB deviation, so its eight balanced armatures and dynamic woofer blend into a cohesive, gently warm tuning. The tradeoff: Air above 10 kHz runs about 3.4 dB above target and a 4 dB peak sits near 8.1 kHz, which can add a slightly bright edge to cymbals.
Why pick the Moondrop Harmon: Across 10 hobbyist measurements on squig.link it scores 82 for preference, with bass held within about half a decibel of target down to 20 Hz, so low end is clean and controlled. Watch for: A deep 6.9 dB dip near 10.3 kHz and treble about 2 dB under target from 6 to 10 kHz make cymbals and acoustic detail sound subdued.
Buy the EPZ K9 or the Moondrop Harmon on features: they are rated the same for sound quality at close to the same price.
Still deciding? The full Headphones rankings cover every ranked option.
Specifications Side By Side
| EPZ K9 | Moondrop Harmon | |
|---|---|---|
| Price | $349.99 | $349.99 |
| Ranked | #34 of 450 in In-Ear Headphones | #38 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 82 (median of 20 squig.link measurements, calibrated to AutoEQ) | 82 (median of 10 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 1.25 dB standard deviation | 1.34 dB standard deviation |
| Tonal Tilt | -0.15 (negative is warmer, positive brighter) | -0.26 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-1.2 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-0.1 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (1 dynamic + 8 balanced armature) | Dynamic |
| Drivers | 1 x dynamic + 8 x balanced armature | 3 x 10mm dynamic |
| Impedance | 14 ohms | 19 ohms |
| Sensitivity | 108 dB | 114 dB/Vrms |
| Frequency Response | - | 10Hz - 60kHz (Manufacturer specified) |
| Built-in Microphone | - | No |
Related Headphone Comparisons
How EPZ K9 compares with other leading options:
- IOAudio Sogno vs EPZ K9
- EPZ K9 vs Tanchjim Soda
- EPZ K9 vs Inawaken Twilight-DS
- Moondrop Harmon vs Inawaken Twilight-DS
- Moondrop Harmon vs Tanchjim Soda
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
EPZ K9: $349.99 Amazon eBay
Pros: In the median of 19 hobbyist measurements on squig.link, the K9 earns a preference score of 82 with a low 1.26 dB deviation, so its eight balanced armatures and dynamic woofer blend into a cohesive, gently warm tuning. Sub-bass is within half a decibel of target and bass about 1.9 dB above it, giving a full low end without boom. The 14 ohm, 108 dB sensitivity rating means it plays loud from a phone.
Cons: Air above 10 kHz runs about 3.4 dB above target and a 4 dB peak sits near 8.1 kHz, which can add a slightly bright edge to cymbals. It is rated below the similarly priced AKG N5005 and IOAudio Sogno, which makes it a harder sell at this price. The very low 14 ohm impedance can make the tuning shift on sources with high output impedance.
Full EPZ K9 review and specifications →
| Back | Closed |
|---|---|
| Connection | Wired |
| Deviation From Target | 1.25 dB standard deviation |
| Driver Type | Hybrid (1 dynamic + 8 balanced armature) |
| Drivers | 1 x dynamic + 8 x balanced armature |
| Form Factor | In-ear |
| Harman Preference Score | 82 (median of 20 squig.link measurements, calibrated to AutoEQ) |
| Impedance | 14 ohms |
| Sensitivity | 108 dB |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-1.2 dB at 30 Hz) |
| Tonal Tilt | -0.15 (negative is warmer, positive brighter) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Moondrop Harmon: $349.99 Amazon eBay
Pros: Across 10 hobbyist measurements on squig.link it scores 82 for preference, with bass held within about half a decibel of target down to 20 Hz, so low end is clean and controlled. Three 10 mm dynamic drivers at 114 dB/Vrms play loudly from a phone. The slightly warm, relaxed tuning suits listeners who are sensitive to treble glare.
Cons: A deep 6.9 dB dip near 10.3 kHz and treble about 2 dB under target from 6 to 10 kHz make cymbals and acoustic detail sound subdued. Its rating sits below the IOAudio Sogno and AKG N5005 at a similar price, and there is no built-in microphone.
Full Moondrop Harmon review and specifications →
| Released | May 2025 (1 year ago) |
|---|---|
| Back | Closed |
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 1.34 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 3 x 10mm dynamic |
| Form Factor | In-ear |
| Frequency Response | 10Hz - 60kHz (Manufacturer specified) |
| Harman Preference Score | 82 (median of 10 squig.link measurements, calibrated to AutoEQ) |
| Impedance | 19 ohms |
| Sensitivity | 114 dB/Vrms |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.1 dB at 30 Hz) |
| Tonal Tilt | -0.26 (negative is warmer, positive brighter) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons