The Dan Clark Audio E3 is 27Ω at 90.0 dB/mW; the Dan Clark Audio Expanse is 26Ω 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.
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.
| Specification | E3 | Expanse |
|---|---|---|
| Impedance | 27 Ω | 26 Ω |
| Sensitivity | 90.0 dB/mW | 90.0 dB/mW |
| Sensitivity (voltage) | 105.7 dB/V | 105.9 dB/V |
| Power for 100 dB | 10 mW | 10 mW |
| Voltage for 100 dB | 0.52 V | 0.51 V |
| Current for 100 dB | 19.2 mA | 19.6 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 3.38 Ω | 3.25 Ω |
| Sources that reach 100 dB out of 280 | 280 | 279 |
1 of the 280 sources has the power for the E3 but not for the Expanse — Steinberg UR22C.
279 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 E3 is more demanding than 87% of the 567 non-electrostatic models in this database; the Expanse than 87%. 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 | E3 power | E3 voltage | Expanse power | Expanse voltage |
|---|---|---|---|---|
| 80 | 0.10 mW | 52 mV | 0.10 mW | 51 mV |
| 85 | 0.32 mW | 92 mV | 0.32 mW | 91 mV |
| 90 | 1.0 mW | 0.16 V | 1.0 mW | 0.16 V |
| 95 | 3.2 mW | 0.29 V | 3.2 mW | 0.29 V |
| 100 | 10 mW | 0.52 V | 10 mW | 0.51 V |
| 105 | 32 mW | 0.92 V | 32 mW | 0.91 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, E3 | Headroom, Expanse | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 4.0 dB | 3.9 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 13.1 dB | 13.2 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 5.1 dB | 5.2 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 279 reach 100 dB on both. That is the easy axis. 70 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 207 of them are in the second group.
The cheapest of the 70 is the JadeAudio JA11, at $20. It leaves 4.0 dB of headroom on the E3 and 3.9 dB on the Expanse, its output impedance is 0.5 Ω against a one-eighth limit of 3.38 Ω and 3.25 Ω, and its noise figure puts the hiss floor 30 dB and 30 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 |
|---|---|---|---|
| E3 | “Yes, it has one” | not printed | not printed |
| Expanse | “Yes, it has one” | not printed | not printed |
Dan Clark Audio prints the same thing for both the E3 and the Expanse: “Yes, it has one”.
For both: The specification table has a frequency-response row. The value printed in it is the sentence "Yes, it has one".
Neither sheet prints a frequency range, and in both cases that is on purpose: the row is there and what stands in it is a sentence rather than a number. It is a better argument than most of this page. A range printed without a tolerance says nothing about how loud a headphone is at either end of it, and of the 490 models whose maker prints a range, 58 print the ±dB figure that would make the range mean something.
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: Dan Clark Audio E3 and Dan Clark Audio Expanse. Every figure on this page comes from what Dan Clark Audio published, or is derived from it — what that maker publishes, counted.