The Dan Clark Audio AEON 2 Closed is 13Ω at 90.0 dB/mW; the Fostex T50RP MK3 is 50Ω at 92.0 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 Dan Clark Audio AEON 2 Closed needs 2.0 dB more than the Fostex T50RP MK3 to reach the same loudness — 10 mW against 6.3 mW.
| Specification | Dan Clark Audio AEON 2 Closed | Fostex T50RP MK3 |
|---|---|---|
| Impedance | 13 Ω | 50 Ω |
| Sensitivity | 90.0 dB/mW | 92.0 dB/mW |
| Sensitivity (voltage) | 108.9 dB/V | 105.0 dB/V |
| Power for 100 dB | 10 mW | 6.3 mW |
| Voltage for 100 dB | 0.36 V | 0.56 V |
| Current for 100 dB | 27.7 mA | 11.2 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.62 Ω | 6.25 Ω |
| Sources that reach 100 dB out of 280 | 272 | 280 |
8 of the 280 sources have the power for the Fostex T50RP MK3 but not for the Dan Clark Audio AEON 2 Closed — Apple USB-C dongle (EU), Zoom AMS-22, Audient EVO 4, 5 more.
6 sources are low enough in output impedance for the Fostex T50RP MK3 under the one-eighth rule but not for the Dan Clark Audio AEON 2 Closed (FiiO KA13, Schiit Vali 2+, Astell&Kern HC3, 3 more).
272 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: Dan Clark Audio AEON 2 Closed and Fostex T50RP MK3. Every figure on this page comes from what Dan Clark Audio and Fostex published, or is derived from it — what Dan Clark Audio publishes and what Fostex publishes, both counted.