HiFiMAN Arya Organic vs ZMF Atrium: which needs more amplifier?

The HiFiMAN Arya Organic is 16Ω at 94.0 dB (no reference unit printed); the ZMF Atrium is 300Ω at 96.0 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 HiFiMAN Arya Organic needs 2.0 dB more than the ZMF Atrium to reach the same loudness — 4.0 mW against 2.5 mW.

The numbers that decide it

SpecificationHiFiMAN Arya OrganicZMF Atrium
Impedance16 Ω300 Ω
Sensitivity94.0 dB96.0 dB/mW
Sensitivity (voltage)112.0 dB/V101.2 dB/V
Power for 100 dB4.0 mW2.5 mW
Voltage for 100 dB0.25 V0.87 V
Current for 100 dB15.8 mA2.9 mA
Highest source impedance
that leaves them alone (one-eighth rule)
2.00 Ω37.50 Ω
Sources that reach 100 dB
out of 280
280277

One caution before reading the rows. HiFiMAN Arya Organic printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, that model needs far more than the table says. Why the two readings differ by so much.

Where the two part company

3 of the 280 sources have the power for the HiFiMAN Arya Organic but not for the ZMF Atrium — Apple USB-C dongle (EU), Steinberg UR22C, Sony NW-A306.

20 sources are low enough in output impedance for the ZMF Atrium under the one-eighth rule but not for the HiFiMAN Arya Organic (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 17 more).

277 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.

Both pages in full

Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: HiFiMAN Arya Organic and ZMF Atrium. Each figure on this page is labelled on those pages with where it came from, including the ones HiFiMAN and ZMF never published — what HiFiMAN publishes and what ZMF publishes, both counted.