The Focal Clear MG Professional is 55Ω at 104.0 dB/mW; the Focal Elegia is 35Ω at 105.0 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 Clear MG Professional needs 1.0 dB more than the Elegia to reach the same loudness — 0.40 mW against 0.32 mW.
| Specification | Clear MG Professional | Elegia |
|---|---|---|
| Impedance | 55 Ω | 35 Ω |
| Sensitivity | 104.0 dB/mW | 105.0 dB/mW |
| Sensitivity (voltage) | 116.6 dB/V | 119.6 dB/V |
| Power for 100 dB | 0.40 mW | 0.32 mW |
| Voltage for 100 dB | 0.15 V | 0.11 V |
| Current for 100 dB | 2.7 mA | 3.0 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 6.88 Ω | 4.38 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
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.
1 source is low enough in output impedance for the Clear MG Professional under the one-eighth rule but not for the Elegia (Shanling H5).
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.
The gap between these two in decibels does not change with volume — it is a property of the two headphones. What changes is the size of the numbers, and it changes fast: every 10 dB costs ten times the power. The row that matters is the one nearest the level you listen at, and for most people that is nearer the top of this table than the bottom.
The Clear MG Professional is more demanding than 46% of the 567 non-electrostatic models in this database; the Elegia than 34%. Both figures use the same measure as the rest of the site: whichever runs out first against a 2 V, 100 mW dongle, voltage or power.
| dB SPL | Clear MG Professional power | Clear MG Professional voltage | Elegia power | Elegia voltage |
|---|---|---|---|---|
| 80 | 4.0 µW | 15 mV | 3.2 µW | 11 mV |
| 85 | 0.01 mW | 26 mV | 0.01 mW | 19 mV |
| 90 | 0.04 mW | 47 mV | 0.03 mW | 33 mV |
| 95 | 0.13 mW | 83 mV | 0.10 mW | 59 mV |
| 100 | 0.40 mW | 0.15 V | 0.32 mW | 0.11 V |
| 105 | 1.3 mW | 0.26 V | 1.0 mW | 0.19 V |
105 dB is included because forum power figures are usually quoted there or higher. It is also a level that damages hearing in minutes — how many minutes is its own calculator.
| Source | Price | Headroom, Clear MG Professional | Headroom, Elegia | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 16.4 dB | 19.4 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 24.7 dB | 27.6 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 16.4 dB | 19.4 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. That is the easy axis. 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 rest either fail one of those or never printed the number at all, and 208 of them are in the second group.
The cheapest of the 69 is the JadeAudio JA11, at $20. It leaves 16.4 dB of headroom on the Clear MG Professional and 19.4 dB on the Elegia, its output impedance is 0.5 Ω against a one-eighth limit of 6.88 Ω and 4.38 Ω, and its noise figure puts the hiss floor 19 dB and 16 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
Cheapest that satisfies three published numbers is not the same as best, and none of it is about how either headphone sounds. To put either model against a source this page does not mention, or to change the target loudness, use the amplifier matcher.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Clear MG Professional | 5 Hz – 23 kHz | ±3 dB | not printed |
| Elegia | 5 Hz-23 kHz | not printed | not printed |
Focal prints 5 Hz – 23 kHz for the Clear MG Professional and 5 Hz-23 kHz for the Elegia.
Clear MG Professional: Focal puts the tolerance in the row heading rather than beside the numbers: the label itself reads "Frequency response (+/- 3dB)".
Only one of the two is a specification. The range printed for the Clear MG Professional comes with a tolerance; the one printed for the Elegia does not, and a range without a ±dB figure says nothing about how loud that model is at either end of it. The two cannot be compared number against number, however similar they look in the table. Of the 490 models whose maker prints a range, 58 print the tolerance.
None of this is a measurement. What each maker publishes, and what it is worth, is set out in the frequency response audit.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Focal Clear MG Professional and Focal Elegia. Every figure on this page comes from what Focal published, or is derived from it — what that maker publishes, counted.