Short answer
Both are audio interfaces, $410 against $432.
The Focusrite Scarlett 16i16 (4th Gen) reaches 100 dB on 553 of the 567 models here, the Roland Rubix44 on 542.
| Specification | Focusrite Scarlett 16i16 (4th Gen) | Roland Rubix44 |
|---|---|---|
| Power into 32Ω | 55 mW | 19 mW |
| Power into 150Ω | 27 mW | 15 mW |
| Power into 300Ω | 27 mW | 9.4 mW |
| Power into 600Ω | 14 mW | 5.4 mW |
| Output impedance | 11 Ω | 47 Ω |
| Output noise | not published | not published |
| Price | $410 | $432 |
| Headphones it reaches 100 dB on out of 567 | 553 | 542 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Focusrite Scarlett 16i16 (4th Gen) | Roland Rubix44 |
|---|---|---|
| 32 Ω | Derived | Derived |
| 150 Ω | Derived | Derived |
| 300 Ω | Published | Derived |
| 600 Ω | Derived | Derived |
Only one of these two columns starts from a power rating. Focusrite Scarlett 16i16 (4th Gen) publishes one at 300 Ω; Roland Rubix44 publishes none at any of these four loads, so its column is worked out from power it published at other loads. Both are arithmetic on a maker’s own figures rather than guesses, and the method used for the Roland Rubix44 understates rather than flatters — but at 300 Ω is the only load here at which its maker can be held to a figure.
11 headphones reach 100 dB on the Focusrite Scarlett 16i16 (4th Gen) but not on the Roland Rubix44 — Audeze LCD-5, Dan Clark Audio AEON 2 Closed, Dan Clark Audio AEON 2 Noire, 8 more.
41 headphones are left alone by the Focusrite Scarlett 16i16 (4th Gen) under the one-eighth rule but coloured by the Roland Rubix44 (AKG K612 Pro, Audeze LCD-3, Audeze LCD-4, 38 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 Sennheiser HD 600: Focusrite Scarlett 16i16 (4th Gen) has +6 dB of headroom there against +2 dB. 5 dB is about 2.9 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Focusrite Scarlett 16i16 (4th Gen) and Roland Rubix44 because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Focusrite Scarlett 16i16 (4th Gen) headroom | Roland Rubix44 headroom | Focusrite Scarlett 16i16 (4th Gen) hiss | Roland Rubix44 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +26 dB damping | +21 dB damping | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +6 dB damping | +1 dB damping | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +16 dB damping | +13 dB damping | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +16 dB | +12 dB damping | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +7 dB damping | +3 dB damping | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +10 dB | +6 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +6 dB | +2 dB damping | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | -1 dB damping | -4 dB damping | not published | not published |
The Roland Rubix44 costs $22 more than the Focusrite Scarlett 16i16 (4th Gen), and on these three axes the money buys nothing: among the 567 models here there is not one that the Roland Rubix44 handles and the Focusrite Scarlett 16i16 (4th Gen) does not — not on power, not on the one-eighth rule, not on hiss. The traffic runs the other way: the cheaper Focusrite Scarlett 16i16 (4th Gen) drives 11 models to 100 dB and leaves 41 alone under the one-eighth rule that the Roland Rubix44 does not.
Only published figures count here; blank axes are counted separately.
Each in full: Focusrite Scarlett 16i16 (4th Gen) and Roland Rubix44.