The Moondrop Armature Art 24 is 5.8Ω at 96.6 dB/mW; the Moondrop Starfield II is 15Ω at 103.8 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The Armature Art 24 needs 7.2 dB more than the Starfield II to reach the same loudness — 2.2 mW against 0.42 mW.
| Specification | Armature Art 24 | Starfield II |
|---|---|---|
| Impedance | 5.8 Ω | 15 Ω |
| Sensitivity | 96.6 dB/mW | 103.8 dB/mW |
| Sensitivity (voltage) | 119.0 dB/V | 122.0 dB/V |
| Power for 100 dB | 2.2 mW | 0.42 mW |
| Voltage for 100 dB | 0.11 V | 79 mV |
| Current for 100 dB | 19.4 mA | 5.3 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 0.72 Ω | 1.88 Ω |
| Sources that reach 100 dB out of 280 | 279 | 280 |
1 of the 280 sources has the power for the Starfield II but not for the Armature Art 24 — Steinberg UR22C.
46 sources are low enough in output impedance for the Starfield II under the one-eighth rule but not for the Armature Art 24 (FiiO SnowSky Tiny B, FiiO KA13, FiiO KA15, 43 more).
2 sources stay below the audible-hiss threshold with the Armature Art 24 but cross it with the Starfield II (FiiO BTR11, Rupert Neve RNHP).
279 of the 280 sources here reach 100 dB on both.
The Armature Art 24 is more demanding than 37% of the 567 non-electrostatic models in this database; the Starfield II than 25%.
| dB SPL | Armature Art 24 power | Armature Art 24 voltage | Starfield II power | Starfield II voltage |
|---|---|---|---|---|
| 80 | 0.02 mW | 11 mV | 4.2 µW | 8 mV |
| 85 | 0.07 mW | 20 mV | 0.01 mW | 14 mV |
| 90 | 0.22 mW | 36 mV | 0.04 mW | 25 mV |
| 95 | 0.69 mW | 63 mV | 0.13 mW | 44 mV |
| 100 | 2.2 mW | 0.11 V | 0.42 mW | 79 mV |
| 105 | 6.9 mW | 0.20 V | 1.3 mW | 0.14 V |
| Source | Price | Headroom, Armature Art 24 | Headroom, Starfield II | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 4.0 dB | 15.3 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 16.1 dB | 27.4 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 13.0 dB | 24.3 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 279 reach 100 dB on both. 41 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.
The cheapest of the 41 is the JadeAudio JA11, at $20. It leaves 4.0 dB of headroom on the Armature Art 24 and 15.3 dB on the Starfield II, its output impedance is 0.5 Ω against a one-eighth limit of 0.72 Ω and 1.88 Ω, and its noise figure puts the hiss floor 16 dB and 13 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Armature Art 24 | 7Hz-35kHz | not printed | not printed |
| 20Hz-20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 | |
| Starfield II | 12Hz-24kHz (IEC61094, Free Field) | not printed | IEC61094 (free field) |
| 20Hz-20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 |
Moondrop prints two ranges, “7Hz-35kHz” and “20Hz-20kHz (IEC60318-4, -3dB)”, for the Armature Art 24 and two ranges, “12Hz-24kHz (IEC61094, Free Field)” and “20Hz-20kHz (IEC60318-4, -3dB)”, for the Starfield II.
Both sheets print a tolerance, which is rare enough to be worth pointing at: only 58 of the 490 models with a printed range do. These two ranges can be set against each other, because each of them says how far down the response is allowed to be at the ends.
Not a measurement; maker by maker.
Both have a page of their own. In full: Moondrop Armature Art 24 and Moondrop Starfield II. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.