Dan Clark Audio Expanse vs HiFiMAN Susvara: which needs more amplifier?

The Dan Clark Audio Expanse is 26Ω 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 Dan Clark Audio Expanse to reach the same loudness — 50 mW against 10 mW.

The numbers that decide it

SpecificationDan Clark Audio ExpanseHiFiMAN Susvara
Impedance26 Ω60 Ω
Sensitivity90.0 dB/mW83.0 dB
Sensitivity (voltage)105.9 dB/V95.2 dB/V
Power for 100 dB10 mW50 mW
Voltage for 100 dB0.51 V1.73 V
Current for 100 dB19.6 mA28.9 mA
Highest source impedance
that leaves them alone (one-eighth rule)
3.25 Ω7.50 Ω
Sources that reach 100 dB
out of 280
279231

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

48 of the 280 sources have the power for the Dan Clark Audio Expanse but not for the HiFiMAN Susvara — Apple USB-C dongle (US), Apple USB-C dongle (EU), Generic CX31993 dongles, 45 more.

1 source is low enough in output impedance for the HiFiMAN Susvara under the one-eighth rule but not for the Dan Clark Audio Expanse (Shanling H5).

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