The Moondrop Armature Art 12 is 5Ω at 98.0 dB/mW; the Moondrop Armature Art 24 is 5.8Ω at 96.6 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The Armature Art 24 needs 1.4 dB more than the Armature Art 12 to reach the same loudness — 2.2 mW against 1.6 mW.
| Specification | Armature Art 12 | Armature Art 24 |
|---|---|---|
| Impedance | 5 Ω | 5.8 Ω |
| Sensitivity | 98.0 dB/mW | 96.6 dB/mW |
| Sensitivity (voltage) | 121.0 dB/V | 119.0 dB/V |
| Power for 100 dB | 1.6 mW | 2.2 mW |
| Voltage for 100 dB | 89 mV | 0.11 V |
| Current for 100 dB | 17.8 mA | 19.4 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 0.62 Ω | 0.72 Ω |
| Sources that reach 100 dB out of 280 | 280 | 279 |
1 of the 280 sources has the power for the Armature Art 12 but not for the Armature Art 24 — Steinberg UR22C.
5 sources are low enough in output impedance for the Armature Art 24 under the one-eighth rule but not for the Armature Art 12 (FiiO KA11, JDS Labs Atom+ (2nd gen), JDS Labs Atom Amp 2, 2 more).
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 Armature Art 12 than 28%.
| dB SPL | Armature Art 12 power | Armature Art 12 voltage | Armature Art 24 power | Armature Art 24 voltage |
|---|---|---|---|---|
| 80 | 0.02 mW | 9 mV | 0.02 mW | 11 mV |
| 85 | 0.05 mW | 16 mV | 0.07 mW | 20 mV |
| 90 | 0.16 mW | 28 mV | 0.22 mW | 36 mV |
| 95 | 0.50 mW | 50 mV | 0.69 mW | 63 mV |
| 100 | 1.6 mW | 89 mV | 2.2 mW | 0.11 V |
| 105 | 5.0 mW | 0.16 V | 6.9 mW | 0.20 V |
| Source | Price | Headroom, Armature Art 12 | Headroom, Armature Art 24 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 4.7 dB | 4.0 dB | 0.5 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 9.5 dB | 8.7 dB | 0.5 Ω | 8.0 µV |
| FiiO BTR13 | $59 | 13.7 dB | 13.0 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 279 reach 100 dB on both. 39 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 39 is the JadeAudio JA11, at $20. It leaves 4.7 dB of headroom on the Armature Art 12 and 4.0 dB on the Armature Art 24, its output impedance is 0.5 Ω against a one-eighth limit of 0.62 Ω and 0.72 Ω, and its noise figure puts the hiss floor 14 dB and 16 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 12 | 6Hz-34kHz | not printed | not printed |
| 20Hz-20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 | |
| Armature Art 24 | 7Hz-35kHz | not printed | not printed |
| 20Hz-20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 |
Moondrop prints two ranges, “6Hz-34kHz” and “20Hz-20kHz (IEC60318-4, -3dB)”, for the Armature Art 12 and two ranges, “7Hz-35kHz” and “20Hz-20kHz (IEC60318-4, -3dB)”, for the Armature Art 24.
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 12 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.