The Letshuoer Mystic 8 is 18Ω at 107.0 dB (no reference unit printed); the Letshuoer S15 is 30Ω at 106.0 dB (no reference unit printed). This page covers what they ask of an amplifier, not how they sound.
The S15 needs 1.0 dB more than the Mystic 8 to reach the same loudness — 0.25 mW against 0.20 mW.
| Specification | Mystic 8 | S15 |
|---|---|---|
| Impedance | 18 Ω | 30 Ω |
| Sensitivity | 107.0 dB | 106.0 dB |
| Sensitivity (voltage) | 124.4 dB/V | 121.2 dB/V |
| Power for 100 dB | 0.20 mW | 0.25 mW |
| Voltage for 100 dB | 60 mV | 87 mV |
| Current for 100 dB | 3.3 mA | 2.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 2.25 Ω | 3.75 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. Letshuoer Mystic 8 and Letshuoer S15 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 S15 but cross it with the Mystic 8 (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 S15 is more demanding than 27% of the 567 non-electrostatic models in this database; the Mystic 8 than 17%.
| dB SPL | Mystic 8 power | Mystic 8 voltage | S15 power | S15 voltage |
|---|---|---|---|---|
| 80 | 2.0 µW | 6 mV | 2.5 µW | 9 mV |
| 85 | 6.3 µW | 11 mV | 7.9 µW | 15 mV |
| 90 | 0.02 mW | 19 mV | 0.03 mW | 27 mV |
| 95 | 0.06 mW | 34 mV | 0.08 mW | 49 mV |
| 100 | 0.20 mW | 60 mV | 0.25 mW | 87 mV |
| 105 | 0.63 mW | 0.11 V | 0.79 mW | 0.15 V |
| Source | Price | Headroom, Mystic 8 | Headroom, S15 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 19.3 dB | 20.5 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 30.7 dB | 29.1 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 27.6 dB | 26.0 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 19.3 dB of headroom on the Mystic 8 and 20.5 dB on the S15, its output impedance is 0.5 Ω against a one-eighth limit of 2.25 Ω and 3.75 Ω, and its noise figure puts the hiss floor 11 dB and 14 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Mystic 8 | nothing printed | — | — |
| S15 | nothing printed | — | — |
Letshuoer prints the same thing for both the Mystic 8 and the S15: nothing at all.
There is nothing here to compare, and that is worth saying plainly rather than filling the gap with somebody else’s measurement. Of the 578 models checked against a maker document so far, 490 carry a printed range and only 58 of those print the ±dB tolerance that would make a range mean anything.
Not a measurement; maker by maker.
Both have a page of their own. In full: Letshuoer Mystic 8 and Letshuoer S15. Each figure on this page is labelled on those pages with where it came from, including the ones Letshuoer never published — what that maker publishes, counted.