Short answer
Both are audio interfaces, $809 against $899.
On raw power they are level: each reaches 100 dB on 565 of the 567 non-electrostatic models here.
| Specification | Audient iD44 MkII | RME Babyface Pro FS |
|---|---|---|
| Power into 32Ω | 190 mW | 374 mW |
| Power into 150Ω | 40 mW | 80 mW |
| Power into 300Ω | 42 mW | 40 mW |
| Power into 600Ω | 54 mW | 20 mW |
| Output impedance | 50 Ω | 10 Ω |
| Output noise | not published | 6.3 µV |
| Price | $809 | $899 |
| Headphones it reaches 100 dB on out of 567 | 565 | 565 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Audient iD44 MkII | RME Babyface Pro FS |
|---|---|---|
| 32 Ω | Derived | Upper bound |
| 150 Ω | Derived | Upper bound |
| 300 Ω | Derived | Upper bound |
| 600 Ω | Published | Upper bound |
These two columns are not the same kind of number, and that matters more than the gap between them. Audient iD44 MkII publishes a power rating (at 600 Ω); RME Babyface Pro FS publishes no power figure at any load, only a maximum output voltage, so every milliwatt in its column is a ceiling worked out from that voltage.
A ceiling assumes the amplifier holds that voltage into the load, and nothing on RME Babyface Pro FS’s own sheet says it does. It is the most flattering reading available, and it is used here only because the alternative is a blank. Where the RME Babyface Pro FS column looks the stronger of the two, treat the difference as unproven rather than measured. 24 of the 280 sources here are in that position, with no published power rating at any load.
On power they are interchangeable across this whole database: there is no headphone here that one reaches 100 dB on and the other does not.
51 headphones are left alone by the RME Babyface Pro FS under the one-eighth rule but coloured by the Audient iD44 MkII (AKG K612 Pro, Audeze LCD-3, Audeze LCD-4, 48 more).
565 of the 567 models here reach 100 dB on both.
Headroom is at a 100 dB SPL peak.
The widest gap on the list is the HiFiMAN Susvara: RME Babyface Pro FS has +6 dB of headroom there against +0 dB. 6 dB is about 3.7 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Audient iD44 MkII because that maker publishes no output noise figure.
| Headphone | Impedance | Needs | Audient iD44 MkII headroom | RME Babyface Pro FS headroom | Audient iD44 MkII hiss | RME Babyface Pro FS hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +32 dB damping | +34 dB damping | not published | 30 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +12 dB damping | +14 dB damping | not published | 10 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +18 dB damping | +23 dB damping | not published | 9 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +18 dB damping | +19 dB | not published | 4 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +13 dB damping | +16 dB damping | not published | 3 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +15 dB | +12 dB | not published | -3 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +8 dB damping | +8 dB | not published | -7 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | +0 dB damping | +6 dB damping | not published | -9 dB |
The RME Babyface Pro FS costs $90 more than the Audient iD44 MkII. Out of the 567 models here, that difference buys 51 more models left alone under the one-eighth rule.
Nothing runs the other way: there is no axis here on which the cheaper of the two does better.
Only published figures count here; blank axes are counted separately.
Each in full: Audient iD44 MkII and RME Babyface Pro FS.