The Dan Clark Audio Expanse is 26Ω at 90.0 dB/mW; the HiFiMAN Edition XV is 12Ω at 92.0 dB (no reference unit printed). 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 Expanse needs 2.0 dB more than the HiFiMAN Edition XV to reach the same loudness — 10 mW against 6.3 mW.
| Specification | Dan Clark Audio Expanse | HiFiMAN Edition XV |
|---|---|---|
| Impedance | 26 Ω | 12 Ω |
| Sensitivity | 90.0 dB/mW | 92.0 dB |
| Sensitivity (voltage) | 105.9 dB/V | 111.2 dB/V |
| Power for 100 dB | 10 mW | 6.3 mW |
| Voltage for 100 dB | 0.51 V | 0.28 V |
| Current for 100 dB | 19.6 mA | 22.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 3.25 Ω | 1.50 Ω |
| Sources that reach 100 dB out of 280 | 279 | 278 |
One caution before reading the rows. HiFiMAN Edition XV printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, that model needs far more than the table says. Why the two readings differ by so much.
1 of the 280 sources has the power for the Dan Clark Audio Expanse but not for the HiFiMAN Edition XV — Apple USB-C dongle (EU).
5 sources are low enough in output impedance for the Dan Clark Audio Expanse under the one-eighth rule but not for the HiFiMAN Edition XV (FiiO KA13, Schiit Vali 2+, Astell&Kern HC3, 2 more).
278 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 Expanse and HiFiMAN Edition XV. Each figure on this page is labelled on those pages with where it came from, including the ones Dan Clark Audio and HiFiMAN never published — what Dan Clark Audio publishes and what HiFiMAN publishes, both counted.