Clear MG Professional vs Elex (Drop): which needs more amplifier?

The Focal Clear MG Professional is 55Ω at 104.0 dB/mW; the Focal Elex (Drop) is 80Ω at 104.0 dB (no figure from the maker at all). This page covers what they ask of an amplifier, not how they sound.

In amplifier terms these two are the same headphone. The gap between what they need for 100 dB is under half a decibel, which is smaller than the step between two clicks of most volume controls.

Side by side

The numbers that decide it

Specification	Clear MG Professional	Elex (Drop)
Impedance	55 Ω	80 Ω
Sensitivity	104.0 dB/mW	104.0 dB
Sensitivity (voltage)	116.6 dB/V	115.0 dB/V
Power for 100 dB	0.40 mW	0.40 mW
Voltage for 100 dB	0.15 V	0.18 V
Current for 100 dB	2.7 mA	2.2 mA
Highest source impedance that leaves them alone (one-eighth rule)	6.88 Ω	10.00 Ω
Sources that reach 100 dB out of 280	280	280

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.

What separates them

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.

9 sources are low enough in output impedance for the Elex (Drop) under the one-eighth rule but not for the Clear MG Professional (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 6 more).

280 of the 280 sources here reach 100 dB on both.

At the level you actually listen at

What each one needs from 80 to 105 dB

The Elex (Drop) is more demanding than 53% of the 567 non-electrostatic models in this database; the Clear MG Professional than 46%.

dB SPL	Clear MG Professional power	Clear MG Professional voltage	Elex (Drop) power	Elex (Drop) voltage
80	4.0 µW	15 mV	4.0 µW	18 mV
85	0.01 mW	26 mV	0.01 mW	32 mV
90	0.04 mW	47 mV	0.04 mW	56 mV
95	0.13 mW	83 mV	0.13 mW	0.10 V
100	0.40 mW	0.15 V	0.40 mW	0.18 V
105	1.3 mW	0.26 V	1.3 mW	0.32 V

What drives both

The cheapest source that satisfies both

Source	Price	Headroom, Clear MG Professional	Headroom, Elex (Drop)	Output impedance	Noise
JadeAudio JA11	$20	16.4 dB	14.8 dB	0.5 Ω	1.7 µV
FiiO KA11	$29	24.7 dB	23.1 dB	0.7 Ω	1.7 µV
FiiO BTR11	$36	16.4 dB	14.7 dB	0.5 Ω	8.0 µV

Of the 280 sources here, 280 reach 100 dB on both. 69 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.

The cheapest of the 69 is the JadeAudio JA11, at $20. It leaves 16.4 dB of headroom on the Clear MG Professional and 14.8 dB on the Elex (Drop), its output impedance is 0.5 Ω against a one-eighth limit of 6.88 Ω and 10.00 Ω, and its noise figure puts the hiss floor 19 dB and 20 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.

Try any other source.

Both pages in full

Both have a page of their own. In full: Focal Clear MG Professional 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.