The Moondrop COSMO is 15Ω at 81.8 dB/mW; the Moondrop SKYLAND is 60Ω at 83.8 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The COSMO needs 2.0 dB more than the SKYLAND to reach the same loudness — 66 mW against 42 mW.
| Specification | COSMO | SKYLAND |
|---|---|---|
| Impedance | 15 Ω | 60 Ω |
| Sensitivity | 81.8 dB/mW | 83.8 dB/mW |
| Sensitivity (voltage) | 100.0 dB/V | 96.0 dB/V |
| Power for 100 dB | 66 mW | 42 mW |
| Voltage for 100 dB | 1.00 V | 1.58 V |
| Current for 100 dB | 66.4 mA | 26.4 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.88 Ω | 7.50 Ω |
| Sources that reach 100 dB out of 280 | 188 | 235 |
2 of the 280 sources have the power for the COSMO but not for the SKYLAND — Tanchjim Stargate II, EarMen Colibri.
49 of the 280 sources have the power for the SKYLAND but not for the COSMO — Fosi Audio N3, iBasso DC03 Pro, Truthear SHIO, 46 more.
4 sources are low enough in output impedance for the SKYLAND under the one-eighth rule but not for the COSMO (Astell&Kern HC3, Shanling H5, RME Fireface UFX II, 1 more).
186 of the 280 sources here reach 100 dB on both.
The SKYLAND is more demanding than 99% of the 567 non-electrostatic models in this database; the COSMO than 99%.
| dB SPL | COSMO power | COSMO voltage | SKYLAND power | SKYLAND voltage |
|---|---|---|---|---|
| 80 | 0.66 mW | 100 mV | 0.42 mW | 0.16 V |
| 85 | 2.1 mW | 0.18 V | 1.3 mW | 0.28 V |
| 90 | 6.6 mW | 0.31 V | 4.2 mW | 0.50 V |
| 95 | 21 mW | 0.56 V | 13 mW | 0.89 V |
| 100 | 66 mW | 1.00 V | 42 mW | 1.58 V |
| 105 | 209 mW | 1.77 V | 132 mW | 2.81 V |
| Source | Price | Headroom, COSMO | Headroom, SKYLAND | Output impedance | Noise |
|---|---|---|---|---|---|
| FiiO KA11 | $29 | 5.4 dB | 4.1 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 2.3 dB | 1.0 dB | 0.6 Ω | 1.0 µV |
| FiiO KA3 | $79 | 2.3 dB | 2.2 dB | 0.5 Ω | 1.7 µV |
Of the 280 sources here, 186 reach 100 dB on both. 66 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 66 is the FiiO KA11, at $29. It leaves 5.4 dB of headroom on the COSMO and 4.1 dB on the SKYLAND, its output impedance is 0.7 Ω against a one-eighth limit of 1.88 Ω and 7.50 Ω, and its noise figure puts the hiss floor 35 dB and 39 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| COSMO | 13Hz- 58kHz (IEC61094, Free Field) | not printed | IEC61094 (free field) |
| 20Hz- 20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 | |
| SKYLAND | 8Hz - 34kHz (IEC61094, FreeField) | not printed | IEC61094 (free field) |
| 20Hz - 20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 |
Moondrop prints two ranges, “13Hz- 58kHz (IEC61094, Free Field)” and “20Hz- 20kHz (IEC60318-4, -3dB)”, for the COSMO and two ranges, “8Hz - 34kHz (IEC61094, FreeField)” and “20Hz - 20kHz (IEC60318-4, -3dB)”, for the SKYLAND.
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 COSMO and Moondrop SKYLAND. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.