The Audeze LCD-X 2021 is 20Ω at 103.0 dB/mW; the Dan Clark Audio AEON 2 Closed is 13Ω at 90.0 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 Dan Clark Audio AEON 2 Closed needs 13.0 dB more than the Audeze LCD-X 2021 to reach the same loudness — 10 mW against 0.50 mW.
| Specification | Audeze LCD-X 2021 | Dan Clark Audio AEON 2 Closed |
|---|---|---|
| Impedance | 20 Ω | 13 Ω |
| Sensitivity | 103.0 dB/mW | 90.0 dB/mW |
| Sensitivity (voltage) | 120.0 dB/V | 108.9 dB/V |
| Power for 100 dB | 0.50 mW | 10 mW |
| Voltage for 100 dB | 0.10 V | 0.36 V |
| Current for 100 dB | 5.0 mA | 27.7 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 2.50 Ω | 1.62 Ω |
| Sources that reach 100 dB out of 280 | 280 | 272 |
8 of the 280 sources have the power for the Audeze LCD-X 2021 but not for the Dan Clark Audio AEON 2 Closed — Apple USB-C dongle (EU), Zoom AMS-22, Audient EVO 4, 5 more.
5 sources are low enough in output impedance for the Audeze LCD-X 2021 under the one-eighth rule but not for the Dan Clark Audio AEON 2 Closed (FiiO KA13, Schiit Vali 2+, Astell&Kern HC3, 2 more).
1 source stays below the audible-hiss threshold with the Dan Clark Audio AEON 2 Closed but crosses it with the Audeze LCD-X 2021 (Schiit Mjolnir 3).
272 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 Dan Clark Audio AEON 2 Closed is more demanding than 80% of the 567 non-electrostatic models in this database; the Audeze LCD-X 2021 than 32%. 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 | Audeze LCD-X 2021 power | Audeze LCD-X 2021 voltage | Dan Clark Audio AEON 2 Closed power | Dan Clark Audio AEON 2 Closed voltage |
|---|---|---|---|---|
| 80 | 5.0 µW | 10 mV | 0.10 mW | 36 mV |
| 85 | 0.02 mW | 18 mV | 0.32 mW | 64 mV |
| 90 | 0.05 mW | 32 mV | 1.0 mW | 0.11 V |
| 95 | 0.16 mW | 56 mV | 3.2 mW | 0.20 V |
| 100 | 0.50 mW | 0.10 V | 10 mW | 0.36 V |
| 105 | 1.6 mW | 0.18 V | 32 mW | 0.64 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, Audeze LCD-X 2021 | Headroom, Dan Clark Audio AEON 2 Closed | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 15.7 dB | 0.9 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 26.5 dB | 13.0 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 18.9 dB | 5.6 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 272 reach 100 dB on both. That is the easy axis. 68 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 200 of them are in the second group.
The cheapest of the 68 is the JadeAudio JA11, at $20. It leaves 15.7 dB of headroom on the Audeze LCD-X 2021 and 0.9 dB on the Dan Clark Audio AEON 2 Closed, its output impedance is 0.5 Ω against a one-eighth limit of 2.50 Ω and 1.62 Ω, and its noise figure puts the hiss floor 15 dB and 27 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 |
|---|---|---|---|
| Audeze LCD-X 2021 | 10Hz - 50kHz | not printed | not printed |
| Dan Clark Audio AEON 2 Closed | “Yes, it has one” | not printed | not printed |
Audeze prints 10Hz - 50kHz for the LCD-X 2021. Dan Clark Audio prints “Yes, it has one” for the AEON 2 Closed.
Dan Clark Audio AEON 2 Closed: The specification table has a frequency-response row. The value printed in it is the sentence "Yes, it has one".
One of these two sheets prints a range and the other prints a sentence declining to, and the second is the more informative of the two. The range given for the Audeze LCD-X 2021 carries no tolerance, so it says nothing about how loud that model is at either end of it — which is exactly the objection the other sheet is making out loud.
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: Audeze LCD-X 2021 and Dan Clark Audio AEON 2 Closed. Every figure on this page comes from what Audeze and Dan Clark Audio published, or is derived from it — what Audeze publishes and what Dan Clark Audio publishes, both counted.