The Symphonium Meteor is 9.7Ω with a sensitivity of 90.9 dB/mW, which is 111.0 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 8.1 mW, or 0.28 V across the drivers.
That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 154 have at least 10 dB of headroom and another 104 have enough. The cheapest portable source that does the job is the Generic CX31993 dongles at $12.
Sensitivity here is in dB per milliwatt. Why the unit matters.
Symphonium publishes this as 111 dB/Vrms (@1kHz) — a figure per volt, not per milliwatt. At 9.7Ω the two differ by 20.1 dB, so the 90.9 dB/mW above is that published number converted, not a different measurement.
This is the conversion that online calculators skip. Quote the per-volt number as if it were per-milliwatt and this headphone looks 20 dB easier to drive than it is — which is roughly the difference between a dongle being enough and not being enough.
Source: symphoniumaudio.com. How this data was built.
| As it is labelled | As printed | Tolerance | Standard |
|---|---|---|---|
| Frequency response | 12Hz - 21kHz, ± 3 dB | ±3 dB | not printed |
Symphonium prints 12Hz - 21kHz, ± 3 dB for the Symphonium Meteor, under the heading “Frequency response”. Source: symphoniumaudio.com.
This is one of only 58 models — out of the 490 whose maker prints a range at all — that also print the tolerance. That is what makes it a specification rather than a headline.
Only what the maker printed; maker by maker.
| Level | What it is | Power | Voltage | Current |
|---|---|---|---|---|
| 85 dB SPL | quiet background listening | 0.26 mW | 50 mV | 5.1 mA |
| 95 dB SPL | normal listening | 2.6 mW | 0.16 V | 16.3 mA |
| 100 dB SPL | loud listening | 8.1 mW | 0.28 V | 28.9 mA |
| 105 dB SPL | very loud | 26 mW | 0.50 V | 51.5 mA |
| 110 dB SPL | peaks on dynamic music | 81 mW | 0.89 V | 91.5 mA |
Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.
The 15 cheapest of the 280 sources here that reach 100 dB SPL into 9.7Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.
| Source | Type | Price | Power into 9.7Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| FiiO KA11 | USB dongle | $29 | 149 mW | +13 dB | Comfortable |
| FiiO KA5 | USB dongle | $99 | 82 mW | +10 dB | Comfortable |
| JDS Labs Atom+ (2nd gen) | desktop amplifier | $99 | 303 mW | +16 dB | Comfortable |
| Schiit Magni Heresy | desktop amplifier | $99 | 1.7 W | +23 dB | Comfortable |
| FiiO BTR15 | Bluetooth receiver | $109 | 100 mW | +11 dB | Comfortable |
| FiiO KA15 | USB dongle | $109 | 176 mW | +13 dB | Comfortable |
| Schiit Magni+ | desktop amplifier | $109 | 606 mW | +19 dB | Comfortable |
| Schiit Magni Unity | desktop amplifier | $119 | 1.8 W | +23 dB | Comfortable |
| JDS Labs Atom Amp 2 | desktop amplifier | $129 | 803 mW | +20 dB | Comfortable |
| Tanchjim LUNA | USB dongle | $140 | 106 mW | +11 dB | Comfortable |
| FiiO K11 | desktop DAC/amp | $143 | 436 mW | +17 dB | Comfortable |
| Topping L30 II | desktop amplifier | $149 | 2.1 W | +24 dB | Comfortable |
| SMSL HO100 | desktop amplifier | $160 | 1.8 W | +23 dB | Comfortable |
| Shanling H2 | portable amplifier | $169 | 206 mW | +14 dB | Comfortable |
| xDuoo MT-604 | desktop amplifier | $169 | 606 mW | +19 dB | Comfortable |
Hiss. At 111.0 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 19 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.
Output impedance. At 9.7Ω these want a source output impedance below 1.21Ω to satisfy the one-eighth rule; 46 of the 192 sources that publish one miss it. Check yours here.
8.5Ω · 83.3 dB/mW · Moderate
See requirements →8.3Ω · 86.2 dB/mW · Easy
See requirements →7.0Ω · 88.5 dB/mW · Easy
See requirements →32Ω · 96.0 dB · Easy
See requirements →45Ω · 98.0 dB/mW · Easy
See requirements →45Ω · 98.0 dB/mW · Easy
See requirements →Compared with its stablemates: vs Crimson · vs Helios · vs Titan · vs Triton · vs Zenith.