Audio-Technica ATH-R70X vs Focal Clear MG: which needs more amplifier?

The Audio-Technica ATH-R70X is 470Ω at 98.0 dB/mW; the Focal Clear MG is 55Ω at 104.0 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 Audio-Technica ATH-R70X needs 6.0 dB more than the Focal Clear MG to reach the same loudness — 1.6 mW against 0.40 mW.

The numbers that decide it

SpecificationAudio-Technica ATH-R70XFocal Clear MG
Impedance470 Ω55 Ω
Sensitivity98.0 dB/mW104.0 dB/mW
Sensitivity (voltage)101.3 dB/V116.6 dB/V
Power for 100 dB1.6 mW0.40 mW
Voltage for 100 dB0.86 V0.15 V
Current for 100 dB1.8 mA2.7 mA
Highest source impedance
that leaves them alone (one-eighth rule)
58.75 Ω6.88 Ω
Sources that reach 100 dB
out of 280
277280

Where the two part company

3 of the 280 sources have the power for the Focal Clear MG but not for the Audio-Technica ATH-R70X — Apple USB-C dongle (EU), Steinberg UR22C, Sony NW-A306.

32 sources are low enough in output impedance for the Audio-Technica ATH-R70X under the one-eighth rule but not for the Focal Clear MG (Zoom AMS-22, Audient EVO 4, ART HeadAmp 4 Pro, 29 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: Audio-Technica ATH-R70X and Focal Clear MG. Every figure on this page comes from what Audio-Technica and Focal published, or is derived from it — what Audio-Technica publishes and what Focal publishes, both counted.