The Tangzu Li Zhi is 18Ω at 107.5 dB (no reference unit printed); the Tangzu Zetian Wu is 16Ω at 100.0 dB (no reference unit printed). This page covers what they ask of an amplifier, not how they sound.
The Zetian Wu needs 7.5 dB more than the Li Zhi to reach the same loudness — 1.0 mW against 0.18 mW.
| Specification | Li Zhi | Zetian Wu |
|---|---|---|
| Impedance | 18 Ω | 16 Ω |
| Sensitivity | 107.5 dB | 100.0 dB |
| Sensitivity (voltage) | 124.9 dB/V | 118.0 dB/V |
| Power for 100 dB | 0.18 mW | 1.0 mW |
| Voltage for 100 dB | 57 mV | 0.13 V |
| Current for 100 dB | 3.1 mA | 7.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 2.25 Ω | 2.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. Tangzu Li Zhi and Tangzu Zetian Wu 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.
9 sources stay below the audible-hiss threshold with the Zetian Wu but cross it with the Li Zhi (FiiO BTR11, FiiO K11 R2R, Lake People G103-S Mk II, 6 more).
280 of the 280 sources here reach 100 dB on both.
The Zetian Wu is more demanding than 40% of the 567 non-electrostatic models in this database; the Li Zhi than 16%.
| dB SPL | Li Zhi power | Li Zhi voltage | Zetian Wu power | Zetian Wu voltage |
|---|---|---|---|---|
| 80 | 1.8 µW | 6 mV | 0.01 mW | 13 mV |
| 85 | 5.6 µW | 10 mV | 0.03 mW | 22 mV |
| 90 | 0.02 mW | 18 mV | 0.10 mW | 40 mV |
| 95 | 0.06 mW | 32 mV | 0.32 mW | 71 mV |
| 100 | 0.18 mW | 57 mV | 1.0 mW | 0.13 V |
| 105 | 0.56 mW | 0.10 V | 3.2 mW | 0.22 V |
| Source | Price | Headroom, Li Zhi | Headroom, Zetian Wu | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 19.8 dB | 11.8 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 31.2 dB | 23.9 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 28.1 dB | 20.8 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 62 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.
The cheapest of the 62 is the JadeAudio JA11, at $20. It leaves 19.8 dB of headroom on the Li Zhi and 11.8 dB on the Zetian Wu, its output impedance is 0.5 Ω against a one-eighth limit of 2.25 Ω and 2.00 Ω, and its noise figure puts the hiss floor 10 dB and 17 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Li Zhi | 20Hz-20.000kHz | not printed | not printed |
| Zetian Wu | 20- 20khz | not printed | not printed |
Tangzu prints 20Hz-20.000kHz for the Li Zhi. Concept Kart, a retailer lists 20- 20khz for the Zetian Wu. That figure stands on Concept Kart, a retailer, not on a document published by the maker.
Li Zhi: Tangzu prints the top of the range as “20.000kHz”. As a decimal point that is 20 kHz; as a thousands separator it would be twenty megahertz. Either way the range it describes is the audible band and nothing beyond it.
Neither range has a tolerance printed beside it, so a wider range on one sheet is not deeper bass or more treble.
Not a measurement; maker by maker.
Both have a page of their own. In full: Tangzu Li Zhi and Tangzu Zetian Wu. 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.