HiFiMAN Edition XV vs Meze 109 Pro: which needs more amplifier?

The HiFiMAN Edition XV is 12Ω at 92.0 dB (no reference unit printed); the Meze 109 Pro is 40Ω at 112.0 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 Edition XV needs 20.0 dB more than the Meze 109 Pro to reach the same loudness — 6.3 mW against 0.06 mW.

The numbers that decide it

SpecificationHiFiMAN Edition XVMeze 109 Pro
Impedance12 Ω40 Ω
Sensitivity92.0 dB112.0 dB/mW
Sensitivity (voltage)111.2 dB/V126.0 dB/V
Power for 100 dB6.3 mW0.06 mW
Voltage for 100 dB0.28 V50 mV
Current for 100 dB22.9 mA1.3 mA
Highest source impedance
that leaves them alone (one-eighth rule)
1.50 Ω5.00 Ω
Sources that reach 100 dB
out of 280
278280

One caution before reading the rows. HiFiMAN Edition XV 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

2 of the 280 sources have the power for the Meze 109 Pro but not for the HiFiMAN Edition XV — Apple USB-C dongle (EU), Steinberg UR22C.

6 sources are low enough in output impedance for the Meze 109 Pro under the one-eighth rule but not for the HiFiMAN Edition XV (FiiO KA13, Schiit Vali 2+, Astell&Kern HC3, 3 more).

13 sources stay below the audible-hiss threshold with the HiFiMAN Edition XV but cross it with the Meze 109 Pro (FiiO BTR11, FiiO K11 R2R, Lake People G103-S Mk II, 10 more).

278 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 Edition XV and Meze 109 Pro. Each figure on this page is labelled on those pages with where it came from, including the ones HiFiMAN and Meze never published — what HiFiMAN publishes and what Meze publishes, both counted.