Focal Clear MG Professional: how much amplifier do you need?

The Focal Clear MG Professional is 55Ω with a sensitivity of 104.0 dB/mW, which is 116.6 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 0.40 mW, or 0.15 V across the drivers.

That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 280 have at least 10 dB of headroom and another 0 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.

The two numbers that decide everything

Impedance55 Ω
Sensitivity104.0 dB/mW
Sensitivity (voltage)116.6 dB/V
Power for 100 dB SPL0.40 mW
Voltage for 100 dB SPL0.15 V
TypeOver-ear
Easy to drive — anything will do it
All 280 sources at 100 dB SPL into 55Ω
Comfortable 280Enough 0Marginal 0Not enough 0
Cheapest portable source that does it
$9 · USB dongle · +17 dB headroom
Cheapest desktop amp with 10 dB to spare
$75 · desktop DAC/amp · +23 dB headroom

Sensitivity here is in dB per milliwatt. Why the unit matters.

Where this sensitivity figure comes from

Focal publishes this directly as 104 dB SPL/mW (1 mW @ 1 kHz), per milliwatt, so nothing was converted.

Source: focal.com. How this data was built.

What is printed there, and what it is worth

As it is labelledAs printedToleranceStandard
Frequency response (+/- 3dB)5 Hz – 23 kHz±3 dBnot printed

Focal prints 5 Hz – 23 kHz for the Focal Clear MG Professional, under the heading “Frequency response (+/- 3dB)”. Source: focal.com.

Focal puts the tolerance in the row heading rather than beside the numbers: the label itself reads "Frequency response (+/- 3dB)".

This is one of only 58 models — out of the 490 whose maker prints a range at all — that also print the tolerance. That is what makes it a specification rather than a headline.

Only what the maker printed; maker by maker.

Power, voltage and current by listening level

LevelWhat it isPowerVoltageCurrent
85 dB SPLquiet background listening0.01 mW26 mV0.5 mA
95 dB SPLnormal listening0.13 mW83 mV1.5 mA
100 dB SPLloud listening0.40 mW0.15 V2.7 mA
105 dB SPLvery loud1.3 mW0.26 V4.8 mA
110 dB SPLpeaks on dynamic music4.0 mW0.47 V8.5 mA

Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.

The cheapest sources that drive them with room to spare

The 15 cheapest of the 280 sources here that reach 100 dB SPL into 55Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.

SourceTypePricePower into 55ΩHeadroomVerdict
FiiO SnowSky Tiny AUSB dongle$2220 mW+17 dBComfortable
FiiO SnowSky Tiny BUSB dongle$2220 mW+17 dBComfortable
Tanchjim Stargate IIUSB dongle$4044 mW+20 dBComfortable
ddHiFi TC35ALUSB dongle$46122 mW+25 dBComfortable
ddHiFi TC35AirUSB dongle$46122 mW+25 dBComfortable
Fosi Audio N3Bluetooth receiver$5080 mW+23 dBComfortable
Hidizs SD2USB dongle$5041 mW+20 dBComfortable
FiiO BTR13Bluetooth receiver$5958 mW+22 dBComfortable
iFi GO linkUSB dongle$5943 mW+20 dBComfortable
Kiwi Ears Allegro ProUSB dongle$6040 mW+20 dBComfortable
ddHiFi TC35Pro (Mountain2)USB dongle$6638 mW+20 dBComfortable
iBasso DC03 ProUSB dongle$6957 mW+22 dBComfortable
DUNU DTC 480USB dongle$7038 mW+20 dBComfortable
EPZ TP35 ProUSB dongle$7065 mW+22 dBComfortable
Tanchjim SpaceUSB dongle$7073 mW+23 dBComfortable

The three ways a source goes wrong

Hiss. At 116.6 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 25 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.

Output impedance. At 55Ω these want a source output impedance below 6.88Ω to satisfy the one-eighth rule; 34 of the 192 sources that publish one miss it. Check yours here.

Similar headphones

Compared with its stablemates: vs Celestee · vs Elear · vs Elegia · vs Elex (Drop).

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