Short answer
Both are audio interfaces, both at $199.
The PreSonus Quantum ES 2 reaches 100 dB on 561 of the 567 models here, the Steinberg UR22C on 512.
| Specification | PreSonus Quantum ES 2 | Steinberg UR22C |
|---|---|---|
| Power into 32Ω | 106 mW | 12 mW |
| Power into 150Ω | 22 mW | 4.0 mW |
| Power into 300Ω | 11 mW | 2.0 mW |
| Power into 600Ω | 5.6 mW | 1.0 mW |
| Output impedance | not published | not published |
| Output noise | not published | not published |
| Price | $199 | $199 |
| Headphones it reaches 100 dB on out of 567 | 561 | 512 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | PreSonus Quantum ES 2 | Steinberg UR22C |
|---|---|---|
| 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 PreSonus Quantum ES 2 figures are ceilings worked out from a maximum output voltage, on the assumption that the amplifier holds it into the load. The Steinberg UR22C 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 PreSonus Quantum ES 2 is the one to doubt.
49 headphones reach 100 dB on the PreSonus Quantum ES 2 but not on the Steinberg UR22C — AKG K612 Pro, Abyss AB-1266 Phi CC, Abyss AB-1266 Phi TC, 46 more.
512 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: PreSonus Quantum ES 2 has +29 dB of headroom there against +19 dB. 9 dB is about 8.8 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for PreSonus Quantum ES 2 and Steinberg UR22C because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | PreSonus Quantum ES 2 headroom | Steinberg UR22C headroom | PreSonus Quantum ES 2 hiss | Steinberg UR22C hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +29 dB | +19 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +9 dB | -1 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +18 dB | +10 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +13 dB | +6 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +10 dB | +1 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +7 dB | -1 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +2 dB | -5 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +1 dB | -7 dB | not published | not published |
These two cost the same, $199, so price settles nothing. Out of the 567 models here, the PreSonus Quantum ES 2 drives 49 models to 100 dB — and on the other side there is no such advantage at all.
Only published figures count here; blank axes are counted separately.
Each in full: PreSonus Quantum ES 2 and Steinberg UR22C.