Celestee vs Elex (Drop): which needs more amplifier?

The Focal Celestee is 35Ω at 105.0 dB/mW; the Focal Elex (Drop) is 80Ω at 104.0 dB (no figure from the maker at all). 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 Elex (Drop) needs 1.0 dB more than the Celestee to reach the same loudness — 0.40 mW against 0.32 mW.

The numbers that decide it

SpecificationCelesteeElex (Drop)
Impedance35 Ω80 Ω
Sensitivity105.0 dB/mW104.0 dB
Sensitivity (voltage)119.6 dB/V115.0 dB/V
Power for 100 dB0.32 mW0.40 mW
Voltage for 100 dB0.11 V0.18 V
Current for 100 dB3.0 mA2.2 mA
Highest source impedance
that leaves them alone (one-eighth rule)
4.38 Ω10.00 Ω
Sources that reach 100 dB
out of 280
280280

One caution before reading the rows. For Focal Elex (Drop) the maker publishes no sensitivity figure at all. The number in the table was collected when this database was first built and has never been traced to a manufacturer document, so treat every row below it as an estimate rather than a specification.

Where the two part company

Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.

10 sources are low enough in output impedance for the Elex (Drop) under the one-eighth rule but not for the Celestee (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 7 more).

280 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: Focal Celestee and Focal Elex (Drop). Each figure on this page is labelled on those pages with where it came from, including the ones Focal never published — what that maker publishes, counted.