The Denon AH-D2000 is 25Ω at 106.0 dB/mW; the Denon AH-D9200 is 24Ω at 105.0 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 AH-D9200 needs 1.0 dB more than the AH-D2000 to reach the same loudness — 0.32 mW against 0.25 mW.
| Specification | AH-D2000 | AH-D9200 |
|---|---|---|
| Impedance | 25 Ω | 24 Ω |
| Sensitivity | 106.0 dB/mW | 105.0 dB/mW |
| Sensitivity (voltage) | 122.0 dB/V | 121.2 dB/V |
| Power for 100 dB | 0.25 mW | 0.32 mW |
| Voltage for 100 dB | 79 mV | 87 mV |
| Current for 100 dB | 3.2 mA | 3.6 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 3.12 Ω | 3.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.
2 sources stay below the audible-hiss threshold with the AH-D9200 but cross it with the AH-D2000 (FiiO BTR11, Rupert Neve RNHP).
280 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: Denon AH-D2000 and Denon AH-D9200. Every figure on this page comes from what Denon published, or is derived from it — what that maker publishes, counted.