The Kinera Mimisbrunnr is 43Ω at 88.3 dB/mW; the Kinera Nott Phantom is 54Ω at 105.0 dB (no reference unit printed). 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 Mimisbrunnr needs 16.7 dB more than the Nott Phantom to reach the same loudness — 15 mW against 0.32 mW.
| Specification | Mimisbrunnr | Nott Phantom |
|---|---|---|
| Impedance | 43 Ω | 54 Ω |
| Sensitivity | 88.3 dB/mW | 105.0 dB |
| Sensitivity (voltage) | 102.0 dB/V | 117.7 dB/V |
| Power for 100 dB | 15 mW | 0.32 mW |
| Voltage for 100 dB | 0.80 V | 0.13 V |
| Current for 100 dB | 18.5 mA | 2.4 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 5.38 Ω | 6.75 Ω |
| Sources that reach 100 dB out of 280 | 277 | 280 |
One caution before reading the rows. Kinera Nott Phantom printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, that model needs far more than the table says. Why the two readings differ by so much.
3 of the 280 sources have the power for the Nott Phantom but not for the Mimisbrunnr — Apple USB-C dongle (EU), Steinberg UR22C, Sony NW-A306.
1 source stays below the audible-hiss threshold with the Mimisbrunnr but crosses it with the Nott Phantom (Schiit Mjolnir 3).
277 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 Mimisbrunnr is more demanding than 96% of the 567 non-electrostatic models in this database; the Nott Phantom than 42%. 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 | Mimisbrunnr power | Mimisbrunnr voltage | Nott Phantom power | Nott Phantom voltage |
|---|---|---|---|---|
| 80 | 0.15 mW | 80 mV | 3.2 µW | 13 mV |
| 85 | 0.47 mW | 0.14 V | 0.01 mW | 23 mV |
| 90 | 1.5 mW | 0.25 V | 0.03 mW | 41 mV |
| 95 | 4.7 mW | 0.45 V | 0.10 mW | 73 mV |
| 100 | 15 mW | 0.80 V | 0.32 mW | 0.13 V |
| 105 | 47 mW | 1.42 V | 1.0 mW | 0.23 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, Mimisbrunnr | Headroom, Nott Phantom | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 1.8 dB | 17.5 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 10.0 dB | 25.7 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 1.8 dB | 17.5 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 277 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 205 of them are in the second group.
The cheapest of the 69 is the JadeAudio JA11, at $20. It leaves 1.8 dB of headroom on the Mimisbrunnr and 17.5 dB on the Nott Phantom, its output impedance is 0.5 Ω against a one-eighth limit of 5.38 Ω and 6.75 Ω, and its noise figure puts the hiss floor 33 dB and 18 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 |
|---|---|---|---|
| Mimisbrunnr | 20Hz – 40kHz | not printed | not printed |
| Nott Phantom | 20Hz - 20kHz full-range | not printed | not printed |
Kinera prints 20Hz – 40kHz for the Mimisbrunnr and 20Hz - 20kHz full-range for the Nott Phantom.
Nott Phantom: The word “full-range” is inside the value, not beside it: Kinera prints it in the same cell as the numbers.
Neither range has a tolerance printed beside it, and that is the whole of what this section can tell you. A wider range on one sheet is not deeper bass or more treble on that headphone: without a tolerance, neither number says how loud either model is at the ends of its own range, so the difference between the two is a difference between two pieces of marketing copy. A ±dB figure is what turns a range into a specification, and of the 490 models whose maker prints a range, 58 print it.
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: Kinera Mimisbrunnr and Kinera Nott Phantom. Each figure on this page is labelled on those pages with where it came from, including the ones Kinera never published — what that maker publishes, counted.