Short answer
Both are audio interfaces, $1399 against $899.
The RME ADI-2 DAC FS reaches 100 dB on 567 of the 567 models here, the RME Babyface Pro FS on 565.
| Specification | RME ADI-2 DAC FS | RME Babyface Pro FS |
|---|---|---|
| Power into 32Ω | 1.2 W | 374 mW |
| Power into 150Ω | 256 mW | 80 mW |
| Power into 300Ω | 128 mW | 40 mW |
| Power into 600Ω | 64 mW | 20 mW |
| Output impedance | 0.1 Ω | 10 Ω |
| Output noise | 2.18 µV | 6.3 µV |
| Price | $1399 | $899 |
| Headphones it reaches 100 dB on out of 567 | 567 | 565 |
| Load | RME ADI-2 DAC FS | RME Babyface Pro FS |
|---|---|---|
| 32 Ω | Published | Upper bound |
| 150 Ω | Derived | Upper bound |
| 300 Ω | Derived | Upper bound |
| 600 Ω | Derived | Upper bound |
These two columns are not the same kind of number, and that matters more than the gap between them. RME ADI-2 DAC FS publishes a power rating (at 32 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.
2 headphones reach 100 dB on the RME ADI-2 DAC FS but not on the RME Babyface Pro FS — Moondrop PARA, Symphonium Titan.
510 headphones are left alone by the RME ADI-2 DAC FS under the one-eighth rule but coloured by the RME Babyface Pro FS (64 Audio Aspire 1, 64 Audio Fourte, 64 Audio Nio, 507 more).
93 headphones stay below the audible-hiss threshold on the RME ADI-2 DAC FS but cross it on the RME Babyface Pro FS (64 Audio Nio, 64 Audio U12t, 64 Audio U18s, 90 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 Shure SE846: RME ADI-2 DAC FS has +41 dB of headroom there against +34 dB. 7 dB is about 5 times the power, which matters for peaks rather than for how loud the music sits.
Hiss below about 20 dB SPL is inaudible in a quiet room.
| Headphone | Impedance | Needs | RME ADI-2 DAC FS headroom | RME Babyface Pro FS headroom | RME ADI-2 DAC FS hiss | RME Babyface Pro FS hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +41 dB | +34 dB damping | 21 dB | 30 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +21 dB | +14 dB damping | 1 dB | 10 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +28 dB | +23 dB damping | -1 dB | 9 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +24 dB | +19 dB | -5 dB | 4 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +21 dB | +16 dB damping | -6 dB | 3 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +17 dB | +12 dB | -12 dB | -3 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +13 dB | +8 dB | -16 dB | -7 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | +11 dB | +6 dB damping | -18 dB | -9 dB |
The RME ADI-2 DAC FS costs $500 more than the RME Babyface Pro FS. Out of the 567 models here, that difference buys 2 more models driven to 100 dB, 510 more models left alone under the one-eighth rule and 93 more models kept below the audible-hiss threshold.
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: RME ADI-2 DAC FS and RME Babyface Pro FS.