COSMO vs PARA: which needs more amplifier?

The Moondrop COSMO is 15Ω at 81.8 dB/mW; the Moondrop PARA is 8Ω at 80.0 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 PARA needs 1.8 dB more than the COSMO to reach the same loudness — 100 mW against 66 mW.

The numbers that decide it

SpecificationCOSMOPARA
Impedance15 Ω8 Ω
Sensitivity81.8 dB/mW80.0 dB/mW
Sensitivity (voltage)100.0 dB/V101.0 dB/V
Power for 100 dB66 mW100 mW
Voltage for 100 dB1.00 V0.89 V
Current for 100 dB66.4 mA111.8 mA
Highest source impedance
that leaves them alone (one-eighth rule)
1.88 Ω1.00 Ω
Sources that reach 100 dB
out of 280
188130

Where the two part company

58 of the 280 sources have the power for the COSMO but not for the PARA — Tanchjim Stargate II, ddHiFi TC35Air, ddHiFi TC35AL, 55 more.

9 sources are low enough in output impedance for the COSMO under the one-eighth rule but not for the PARA (FiiO KA13, FiiO K11, Schiit Vali 2+, 6 more).

130 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: Moondrop COSMO and Moondrop PARA. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.