Short answer
Both are audio interfaces, $649 against $432.
The Apogee Duet 3 reaches 100 dB on 567 of the 567 models here, the Roland Rubix44 on 542.
| Specification | Apogee Duet 3 | Roland Rubix44 |
|---|---|---|
| Power into 32Ω | 1.2 W | 19 mW |
| Power into 150Ω | 252 mW | 15 mW |
| Power into 300Ω | 126 mW | 9.4 mW |
| Power into 600Ω | 63 mW | 5.4 mW |
| Output impedance | 0.5 Ω | 47 Ω |
| Output noise | not published | not published |
| Price | $649 | $432 |
| Headphones it reaches 100 dB on out of 567 | 567 | 542 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Apogee Duet 3 | Roland Rubix44 |
|---|---|---|
| 32 Ω | Upper bound | Derived |
| 150 Ω | Upper bound | Derived |
| 300 Ω | Upper bound | Derived |
| 600 Ω | Upper bound | Derived |
Neither column is a power rating, and the two are not even weak in the same way. The Apogee Duet 3 figures are ceilings worked out from a maximum output voltage, on the assumption that the amplifier holds it into the load. The Roland Rubix44 figures are worked out from figures its maker did publish — power at other loads, or the voltage printed beside it. The second method understates; the first flatters. That is the wrong way round for reading the table straight across, so a gap in favour of the Apogee Duet 3 is the one to doubt.
25 headphones reach 100 dB on the Apogee Duet 3 but not on the Roland Rubix44 — Audeze LCD-5, Dan Clark Audio AEON 2 Closed, Dan Clark Audio AEON 2 Noire, 22 more.
560 headphones are left alone by the Apogee Duet 3 under the one-eighth rule but coloured by the Roland Rubix44 (64 Audio Aspire 1, 64 Audio Fourte, 64 Audio Nio, 557 more).
542 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: Apogee Duet 3 has +39 dB of headroom there against +21 dB. 18 dB is about 61 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Apogee Duet 3 and Roland Rubix44 because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Apogee Duet 3 headroom | Roland Rubix44 headroom | Apogee Duet 3 hiss | Roland Rubix44 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +39 dB | +21 dB damping | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +19 dB | +1 dB damping | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +28 dB | +13 dB damping | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +24 dB | +12 dB damping | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +21 dB | +3 dB damping | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +17 dB | +6 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +13 dB | +2 dB damping | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +11 dB | -4 dB damping | not published | not published |
The Apogee Duet 3 costs $217 more than the Roland Rubix44. Out of the 567 models here, that difference buys 25 more models driven to 100 dB and 560 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: Apogee Duet 3 and Roland Rubix44.