The Focal Elegia is 35Ω at 105.0 dB/mW; the Focal Listen Professional is 32Ω at 107.1 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 Elegia needs 2.1 dB more than the Listen Professional to reach the same loudness — 0.32 mW against 0.19 mW.
| Specification | Elegia | Listen Professional |
|---|---|---|
| Impedance | 35 Ω | 32 Ω |
| Sensitivity | 105.0 dB/mW | 107.1 dB/mW |
| Sensitivity (voltage) | 119.6 dB/V | 122.0 dB/V |
| Power for 100 dB | 0.32 mW | 0.19 mW |
| Voltage for 100 dB | 0.11 V | 79 mV |
| Current for 100 dB | 3.0 mA | 2.5 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 4.38 Ω | 4.00 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 Elegia but cross it with the Listen Professional (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: Focal Elegia and Focal Listen Professional. Every figure on this page comes from what Focal published, or is derived from it — what that maker publishes, counted.