Audeze LCD-5 vs Audio-Technica ATH-R70X: which needs more amplifier?

The Audeze LCD-5 is 14Ω at 90.0 dB/mW; the Audio-Technica ATH-R70X is 470Ω at 98.0 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 Audeze LCD-5 needs 8.0 dB more than the Audio-Technica ATH-R70X to reach the same loudness — 10 mW against 1.6 mW.

The numbers that decide it

SpecificationAudeze LCD-5Audio-Technica ATH-R70X
Impedance14 Ω470 Ω
Sensitivity90.0 dB/mW98.0 dB/mW
Sensitivity (voltage)108.5 dB/V101.3 dB/V
Power for 100 dB10 mW1.6 mW
Voltage for 100 dB0.37 V0.86 V
Current for 100 dB26.7 mA1.8 mA
Highest source impedance
that leaves them alone (one-eighth rule)
1.75 Ω58.75 Ω
Sources that reach 100 dB
out of 280
274277

Where the two part company

1 of the 280 sources has the power for the Audeze LCD-5 but not for the Audio-Technica ATH-R70X — Sony NW-A306.

4 of the 280 sources have the power for the Audio-Technica ATH-R70X but not for the Audeze LCD-5 — Zoom AMS-22, Tascam US-2x2HR, Roland Rubix22, 1 more.

37 sources are low enough in output impedance for the Audio-Technica ATH-R70X under the one-eighth rule but not for the Audeze LCD-5 (Zoom AMS-22, Audient EVO 4, ART HeadAmp 4 Pro, 34 more).

273 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: Audeze LCD-5 and Audio-Technica ATH-R70X. Every figure on this page comes from what Audeze and Audio-Technica published, or is derived from it — what Audeze publishes and what Audio-Technica publishes, both counted.