On power, yes — all of them. Every one of the 65 audio interfaces in this database reaches 100 dB SPL on the Etymotic ER4XR, which needs 1.6 mW at its 45Ω.
Power is one of three questions and the one that goes wrong least often. The other two — whether the source’s output impedance leaves the frequency response alone, and whether you will hear its noise floor — are answered further down, separately, because a source can pass one and fail another.
The cheapest one that does reach it is the Zoom AMS-22 at $100, which delivers 15 mW into 45Ω — 10 dB of headroom over the 1.6 mW this headphone needs for 100 dB SPL.
100 dB SPL is a peak level, not a listening level. If you listen at 85 dB the same headphone needs 0.05 mW, which is 15 dB less, and the answer above changes for most of the category. The model page has the full ladder.
Under the one-eighth rule the Etymotic ER4XR wants a source below 5.62Ω. Of the 43 audio interfaces here that publish an output impedance, 15 are under it and 28 are not.
The furthest over is the Tascam US-2x2HR at 66Ω, which is 12× the ceiling. Above that threshold the source stops being a volume control and starts being part of the frequency response. The simulator shows what that looks like.
The other 22 publish nothing at all on this, so they are not on either side of that count. This site leaves them blank rather than assuming a figure.
Hiss depends on the source’s own noise floor and on how sensitive the headphone is. At 98.0 dB/mW and 45Ω, the Etymotic ER4XR turns one microvolt of source noise into about -9 dB SPL — and the threshold where that stops being noticeable in a quiet room is around 20 dB SPL.
The one audio interface here that publishes a noise figure stays below that threshold with this headphone.
The remaining 64 publish no noise figure, so they cannot be placed on either side.
| Source | Price | Into 45Ω | Output impedance | Hiss in these | Power verdict |
|---|---|---|---|---|---|
| Steinberg IXO22 | $119 | 36 mW | not published | not published | Comfortable |
| IK Multimedia AXE I/O ONE | $130 | 36 mW | <0.1 Ω | not published | Comfortable |
| PreSonus Studio 24c | $149 | 38 mW | not published | not published | Comfortable |
| Universal Audio Volt 1 | $149 | 63 mW | not published | not published | Comfortable |
| Steinberg UR24C | $194 | 89 mW | not published | not published | Comfortable |
| Audient iD4 MkII | $199 | 123 mW | not published | not published | Comfortable |
| PreSonus Quantum ES 2 | $199 | 75 mW | not published | not published | Comfortable |
| Universal Audio Volt 2 | $199 | 63 mW | not published | not published | Comfortable |
| MOTU M2 | $219 | 237 mW | not published | not published | Comfortable |
| SSL 2 MkII | $229 | 266 mW | 1 Ω | not published | Comfortable |
| Focusrite Vocaster Two | $250 | 22 mW | not published | not published | Comfortable |
| MOTU M4 | $279 | 237 mW | not published | not published | Comfortable |
Sorted by how many of the three questions the source answers well, then by price. A blank in a column is a blank in the manufacturer’s own documentation, not a zero.
The Etymotic ER4XR on other categories: desktop amplifiers · desktop DAC/amps.
The Etymotic ER4XR page has every source in the database against this headphone, and the matcher takes your own numbers.