The Moondrop Aria is 32Ω at 107.1 dB/mW; the Moondrop Armature Art 24 is 5.8Ω at 96.6 dB/mW. This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.
The Armature Art 24 needs 10.5 dB more than the Aria to reach the same loudness — 2.2 mW against 0.19 mW.
| Specification | Aria | Armature Art 24 |
|---|---|---|
| Impedance | 32 Ω | 5.8 Ω |
| Sensitivity | 107.1 dB/mW | 96.6 dB/mW |
| Sensitivity (voltage) | 122.0 dB/V | 119.0 dB/V |
| Power for 100 dB | 0.19 mW | 2.2 mW |
| Voltage for 100 dB | 79 mV | 0.11 V |
| Current for 100 dB | 2.5 mA | 19.4 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 4.00 Ω | 0.72 Ω |
| Sources that reach 100 dB out of 280 | 280 | 279 |
1 of the 280 sources has the power for the Aria but not for the Armature Art 24 — Steinberg UR22C.
49 sources are low enough in output impedance for the Aria under the one-eighth rule but not for the Armature Art 24 (FiiO SnowSky Tiny B, FiiO KA13, FiiO KA15, 46 more).
2 sources stay below the audible-hiss threshold with the Armature Art 24 but cross it with the Aria (FiiO BTR11, Rupert Neve RNHP).
279 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Moondrop Aria and Moondrop Armature Art 24. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.