Susvara vs Susvara Unveiled: which needs more amplifier?

The HiFiMAN Susvara is 60Ω at 83.0 dB (no reference unit printed); the HiFiMAN Susvara Unveiled is 45Ω at 86.0 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 Susvara needs 3.0 dB more than the Susvara Unveiled to reach the same loudness — 50 mW against 25 mW.

The numbers that decide it

SpecificationSusvaraSusvara Unveiled
Impedance60 Ω45 Ω
Sensitivity83.0 dB86.0 dB
Sensitivity (voltage)95.2 dB/V99.5 dB/V
Power for 100 dB50 mW25 mW
Voltage for 100 dB1.73 V1.06 V
Current for 100 dB28.9 mA23.6 mA
Highest source impedance
that leaves them alone (one-eighth rule)
7.50 Ω5.62 Ω
Sources that reach 100 dB
out of 280
231259

One caution before reading the rows. HiFiMAN Susvara and HiFiMAN Susvara Unveiled printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, each of them needs far more than the table says. Why the two readings differ by so much.

Where the two part company

28 of the 280 sources have the power for the Susvara Unveiled but not for the Susvara — Generic CX31993 dongles, Tanchjim Stargate II, Hidizs SD2, 25 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: HiFiMAN Susvara and HiFiMAN Susvara Unveiled. Each figure on this page is labelled on those pages with where it came from, including the ones HiFiMAN never published — what that maker publishes, counted.