Moondrop Harmon Cuffie ear loop

Triple-Dynamic In-Ear Monitor with Coaxial Four-Cavity Crossover

The Moondrop Harmon is a universal-fit in-ear monitor that packs three full-size 10mm dynamic drivers into a compact shell. At its core is the patented coaxial four-cavity frequency crossover, which routes each driver through an independent acoustic cavity for precise tuning control. The Harmon delivers a wide-range, impactful sound that fits listeners who want a bass-forward signature without sacrificing midrange clarity.

Built around Moondrop's XTM series platform, this model targets a warm, slightly V-shaped presentation tuned to the brand's VDSF target response, refined through FEA acoustic simulation and subjective fine-tuning.

What Sets the Harmon Apart

Two engineering choices make this IEM stand out in Moondrop's lineup. The mid-treble driver uses an ultra-thin molded glass dome composite diaphragm with a flexible suspension structure, offering higher rigidity and better damping than typical metal diaphragms for cleaner high-frequency extension. The bass section uses Moondrop's signature H.O.D.D.D.U.S. configuration, dual 10mm paper-cone drivers mounted in a horizontally-opposed layout with N52 neodymium magnets and CCAW voice coils, designed to reduce nonlinear distortion and improve dynamic range. The intricate internal shell is produced in partnership with HeyGears using high-precision DLP 3D printing for consistent manufacturing at scale.

Technical Specifications

• Driver Configuration: 1 × 10mm glass dome mid-treble DD + 2 × 10mm paper cone bass DD (H.O.D.D.D.U.S.)
• Frequency Response: 10 Hz – 60 kHz (effective 20 Hz – 20 kHz, IEC60318-4, –3 dB)
• Sensitivity: 114 dB/Vrms @ 1 kHz — easy to drive from phones, dongles, and portable players
• Impedance: 19 Ω ±15% @ 1 kHz — low-impedance load that pairs well with most source devices
• THD: ≤0.1% @ 1 kHz, 94 dB — clean signal at typical listening levels
• Cable: 1.2 m detachable, 0.78mm 2-pin, swappable 3.5mm single-ended and 4.4mm balanced plugs
• Package Contents: earpiece pair, braided cable, ear tips (S/M/L), storage bag, manual, certificate

Who the Moondrop Harmon Is For

The Moondrop Harmon is the right choice for listeners who want a bass-forward triple-dynamic IEM with a refined midrange and don't mind a slightly V-shaped tuning. Its 19 Ω impedance and 114 dB/Vrms sensitivity make it easy to drive straight from a smartphone or laptop, while the swappable 3.5mm and 4.4mm terminations open the door to balanced desktop setups. The 0.78mm 2-pin cable interface also lets users roll aftermarket cables for further customization. Anyone upgrading from a single-DD IEM to a more layered, sub-bass-focused presentation, will find the Harmon a logical step up.