Both are portable players, $199 against $209. This page puts them side by side on the only three things a maker can be held to — power, output impedance and noise — and then asks the question that actually matters: which headphones do they treat differently?
The FiiO JM21 reaches 100 dB on 566 of the 567 models here, the Shanling M1 Plus on 564.
| Specification | FiiO JM21 | Shanling M1 Plus |
|---|---|---|
| Power into 32Ω | 245 mW | 195 mW |
| Power into 150Ω | 56 mW | 42 mW |
| Power into 300Ω | 30 mW | 21 mW |
| Power into 600Ω | 15 mW | 10 mW |
| Output impedance | 1 Ω | 0.6 Ω |
| Output noise | 1.6 µV | not published |
| Price | $199 | $209 |
| Headphones it reaches 100 dB on out of 567 | 566 | 564 |
A figure marked not published is missing from the maker’s own material, which is not the same as being good or bad. Where one of these two publishes a number and the other does not, the comparison on that axis cannot be made at all — and saying so is more useful than guessing.
2 headphones reach 100 dB on the FiiO JM21 but not on the Shanling M1 Plus — Moondrop PARA, Symphonium Crimson.
14 headphones are left alone by the Shanling M1 Plus under the one-eighth rule but coloured by the FiiO JM21 (64 Audio Nio, 64 Audio Volur, Campfire Audio Andromeda 2023, 11 more).
564 of the 567 models here reach 100 dB on both. That is a power count and nothing more; whether either source suits a given headphone also depends on the two lines above.
Each has a page of its own with every power figure traced to what the maker published and a full headphone list: FiiO JM21 and Shanling M1 Plus. Or put either against your own headphones in the source comparison tool.