Short answer
Both are audio interfaces, $599 against $589.
The Audient iD24 reaches 100 dB on 561 of the 567 models here, the Universal Audio Volt 476P on 558.
| Specification | Audient iD24 | Universal Audio Volt 476P |
|---|---|---|
| Power into 32Ω | 119 mW | 84 mW |
| Power into 150Ω | 80 mW | 28 mW |
| Power into 300Ω | 58 mW | 22 mW |
| Power into 600Ω | 52 mW | 12 mW |
| Output impedance | 50 Ω | not published |
| Output noise | not published | not published |
| Price | $599 | $589 |
| Headphones it reaches 100 dB on out of 567 | 561 | 558 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Audient iD24 | Universal Audio Volt 476P |
|---|---|---|
| 32 Ω | Derived | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Published |
| 600 Ω | Recomputed | Published |
Only one of these two columns starts from a power rating. Universal Audio Volt 476P publishes one at 32 Ω, at 300 Ω and at 600 Ω; Audient iD24 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 Audient iD24 understates rather than flatters — but at 32 Ω, at 300 Ω and at 600 Ω are the only loads here at which its maker can be held to a figure.
3 headphones reach 100 dB on the Audient iD24 but not on the Universal Audio Volt 476P — Moondrop PARA 2, Moondrop VENUS, Symphonium Triton.
558 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 Audio-Technica ATH-R70X: Audient iD24 has +15 dB of headroom there against +10 dB. 6 dB is about 3.6 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Audient iD24 and Universal Audio Volt 476P because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Audient iD24 headroom | Universal Audio Volt 476P headroom | Audient iD24 hiss | Universal Audio Volt 476P hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +29 dB damping | +28 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +9 dB damping | +8 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +22 dB damping | +18 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +20 dB damping | +16 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +11 dB damping | +9 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +15 dB | +10 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +9 dB damping | +5 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +5 dB damping | +0 dB | not published | not published |
The Audient iD24 costs $10 more than the Universal Audio Volt 476P. Out of the 567 models here, that difference buys 3 more models driven to 100 dB.
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 iD24 and Universal Audio Volt 476P.