The Dan Clark Audio AEON 2 Closed is 13Ω at 90.0 dB/mW; the Sennheiser HD 800S is 300Ω at 96.8 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 6.8 dB more than the Sennheiser HD 800S to reach the same loudness — 10 mW against 2.1 mW.
| Specification | Dan Clark Audio AEON 2 Closed | Sennheiser HD 800S |
|---|---|---|
| Impedance | 13 Ω | 300 Ω |
| Sensitivity | 90.0 dB/mW | 96.8 dB/mW |
| Sensitivity (voltage) | 108.9 dB/V | 102.0 dB/V |
| Power for 100 dB | 10 mW | 2.1 mW |
| Voltage for 100 dB | 0.36 V | 0.79 V |
| Current for 100 dB | 27.7 mA | 2.6 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.62 Ω | 37.50 Ω |
| Sources that reach 100 dB out of 280 | 272 | 277 |
1 of the 280 sources has the power for the Dan Clark Audio AEON 2 Closed but not for the Sennheiser HD 800S — Sony NW-A306.
6 of the 280 sources have the power for the Sennheiser HD 800S but not for the Dan Clark Audio AEON 2 Closed — Zoom AMS-22, Audient EVO 4, Tascam US-2x2HR, 3 more.
25 sources are low enough in output impedance for the Sennheiser HD 800S under the one-eighth rule but not for the Dan Clark Audio AEON 2 Closed (FiiO KA13, Zoom AMS-22, Arturia MiniFuse 2, 22 more).
271 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 Sennheiser HD 800S. Every figure on this page comes from what Dan Clark Audio and Sennheiser published, or is derived from it — what Dan Clark Audio publishes and what Sennheiser publishes, both counted.