The Tangzu Li Zhi is 18Ω at 107.5 dB (no reference unit printed); the Tangzu Xuan Nv is 8.5Ω at 98.0 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 Xuan Nv needs 9.5 dB more than the Li Zhi to reach the same loudness — 1.6 mW against 0.18 mW.
| Specification | Li Zhi | Xuan Nv |
|---|---|---|
| Impedance | 18 Ω | 8.5 Ω |
| Sensitivity | 107.5 dB | 98.0 dB |
| Sensitivity (voltage) | 124.9 dB/V | 118.7 dB/V |
| Power for 100 dB | 0.18 mW | 1.6 mW |
| Voltage for 100 dB | 57 mV | 0.12 V |
| Current for 100 dB | 3.1 mA | 13.7 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 2.25 Ω | 1.06 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. Tangzu Li Zhi and Tangzu Xuan Nv printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, each of them needs far more than the table says. Why the two readings differ by so much.
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.
12 sources are low enough in output impedance for the Li Zhi under the one-eighth rule but not for the Xuan Nv (FiiO KA13, FiiO K11, Schiit Vali 2+, 9 more).
8 sources stay below the audible-hiss threshold with the Xuan Nv but cross it with the Li Zhi (FiiO BTR11, FiiO K11 R2R, Lake People G103-S Mk II, 5 more).
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: Tangzu Li Zhi and Tangzu Xuan Nv. Each figure on this page is labelled on those pages with where it came from, including the ones Tangzu never published — what that maker publishes, counted.