The Symphonium Meteor is 9.7Ω at 90.9 dB/mW; the Symphonium Zenith is 6.1Ω at 85.9 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 Zenith needs 5.0 dB more than the Meteor to reach the same loudness — 26 mW against 8.1 mW.
| Specification | Meteor | Zenith |
|---|---|---|
| Impedance | 9.7 Ω | 6.1 Ω |
| Sensitivity | 90.9 dB/mW | 85.9 dB/mW |
| Sensitivity (voltage) | 111.0 dB/V | 108.0 dB/V |
| Power for 100 dB | 8.1 mW | 26 mW |
| Voltage for 100 dB | 0.28 V | 0.40 V |
| Current for 100 dB | 28.9 mA | 64.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.21 Ω | 0.76 Ω |
| Sources that reach 100 dB out of 280 | 271 | 197 |
74 of the 280 sources have the power for the Meteor but not for the Zenith — Apple USB-C dongle (US), Generic CX31993 dongles, JadeAudio JA11, 71 more.
41 sources are low enough in output impedance for the Meteor under the one-eighth rule but not for the Zenith (FiiO SnowSky Tiny B, FiiO KA15, FiiO BTR15, 38 more).
197 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: Symphonium Meteor and Symphonium Zenith. Every figure on this page comes from what Symphonium published, or is derived from it — what that maker publishes, counted.