The Vision Ears EXT MK II is 10Ω at 108.5 dB/mW; the Vision Ears Phönix Final Edition is 10Ω at 114.6 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 EXT MK II needs 6.1 dB more than the Phönix Final Edition to reach the same loudness — 0.14 mW against 0.03 mW.
| Specification | EXT MK II | Phönix Final Edition |
|---|---|---|
| Impedance | 10 Ω | 10 Ω |
| Sensitivity | 108.5 dB/mW | 114.6 dB/mW |
| Sensitivity (voltage) | 128.5 dB/V | 134.6 dB/V |
| Power for 100 dB | 0.14 mW | 0.03 mW |
| Voltage for 100 dB | 38 mV | 19 mV |
| Current for 100 dB | 3.8 mA | 1.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.25 Ω | 1.25 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.
31 sources stay below the audible-hiss threshold with the EXT MK II but cross it with the Phönix Final Edition (Kiwi Ears Allegro Mini, FiiO KA13, JDS Labs Atom+ (2nd gen), 28 more).
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 EXT MK II is more demanding than 6% of the 567 non-electrostatic models in this database; the Phönix Final Edition than 0%. 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 | EXT MK II power | EXT MK II voltage | Phönix Final Edition power | Phönix Final Edition voltage |
|---|---|---|---|---|
| 80 | 1.4 µW | 4 mV | 0.3 µW | 2 mV |
| 85 | 4.5 µW | 7 mV | 1.1 µW | 3 mV |
| 90 | 0.01 mW | 12 mV | 3.5 µW | 6 mV |
| 95 | 0.04 mW | 21 mV | 0.01 mW | 10 mV |
| 100 | 0.14 mW | 38 mV | 0.03 mW | 19 mV |
| 105 | 0.45 mW | 67 mV | 0.11 mW | 33 mV |
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, EXT MK II | Headroom, Phönix Final Edition | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 18.2 dB | 24.3 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 30.4 dB | 36.5 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 27.3 dB | 33.4 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. That is the easy axis. 23 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 23 is the JadeAudio JA11, at $20. It leaves 18.2 dB of headroom on the EXT MK II and 24.3 dB on the Phönix Final Edition, its output impedance is 0.5 Ω against a one-eighth limit of 1.25 Ω for both, and its noise figure puts the hiss floor 7 dB and 1 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 |
|---|---|---|---|
| EXT MK II | nothing printed | — | — |
| Phönix Final Edition | 10 Hz - 25 kHz | not printed | not printed |
Vision Ears prints nothing at all for the EXT MK II and 10 Hz - 25 kHz for the Phönix Final Edition.
Phönix Final Edition: The label on that row is one word: “Frequency”. Not response, not range.
So one side of this comparison has a frequency-response number and the other does not — which changes less than it looks. The range printed for the Phönix Final Edition comes with no tolerance beside it, and a range without a ±dB figure says nothing about how loud the headphone is at either end of it: thirty decibels down at the bottom and the sentence would still be true. On the only reading that would have made it a specification, the two sheets say the same amount: nothing.
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: Vision Ears EXT MK II and Vision Ears Phönix Final Edition. Every figure on this page comes from what Vision Ears published, or is derived from it — what that maker publishes, counted.