Audeze LCD-5 vs HiFiMAN Susvara: which needs more amplifier?

The Audeze LCD-5 is 14Ω at 90.0 dB/mW; the HiFiMAN Susvara is 60Ω at 83.0 dB (no reference unit printed). 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 Susvara needs 7.0 dB more than the Audeze LCD-5 to reach the same loudness — 50 mW against 10 mW.

The numbers that decide it

SpecificationAudeze LCD-5HiFiMAN Susvara
Impedance14 Ω60 Ω
Sensitivity90.0 dB/mW83.0 dB
Sensitivity (voltage)108.5 dB/V95.2 dB/V
Power for 100 dB10 mW50 mW
Voltage for 100 dB0.37 V1.73 V
Current for 100 dB26.7 mA28.9 mA
Highest source impedance
that leaves them alone (one-eighth rule)
1.75 Ω7.50 Ω
Sources that reach 100 dB
out of 280
274231

One caution before reading the rows. HiFiMAN Susvara 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

43 of the 280 sources have the power for the Audeze LCD-5 but not for the HiFiMAN Susvara — Apple USB-C dongle (US), Generic CX31993 dongles, JadeAudio JA11, 40 more.

5 sources are low enough in output impedance for the HiFiMAN Susvara under the one-eighth rule but not for the Audeze LCD-5 (Schiit Vali 2+, Astell&Kern HC3, Shanling H5, 2 more).

231 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 HiFiMAN Susvara. Each figure on this page is labelled on those pages with where it came from, including the ones Audeze and HiFiMAN never published — what Audeze publishes and what HiFiMAN publishes, both counted.