Both are portable players, $649 against $750. This page puts them side by side on the only three things a maker can be held to — power, output impedance and noise — and then asks the question that actually matters: which headphones do they treat differently?
The HiBy R6 Pro II reaches 100 dB on 566 of the 567 models here, the Cayin N3 Ultra on 565.
| Specification | Cayin N3 Ultra | HiBy R6 Pro II |
|---|---|---|
| Power into 32Ω | 250 mW | 750 mW |
| Power into 150Ω | 53 mW | 280 mW |
| Power into 300Ω | 27 mW | 140 mW |
| Power into 600Ω | 13 mW | 70 mW |
| Output impedance | 0.5 Ω | 0.6 Ω unverified |
| Output noise | not published | 4 µV unverified |
| Price | $649 | $750 |
| Headphones it reaches 100 dB on out of 567 | 565 | 566 |
A figure marked not published is missing from the maker’s own material, which is not the same as being good or bad. Where one of these two publishes a number and the other does not, the comparison on that axis cannot be made at all — and saying so is more useful than guessing.
1 headphone reaches 100 dB on the HiBy R6 Pro II but not on the Cayin N3 Ultra — Moondrop PARA.
565 of the 567 models here reach 100 dB on both. That is a power count and nothing more; whether either source suits a given headphone also depends on the two lines above.
Each has a page of its own with a full headphone list and the provenance of every figure — worth opening here, because HiBy R6 Pro II has published no electrical specification at all and everything above comes from independent measurement: Cayin N3 Ultra and HiBy R6 Pro II. Or put either against your own headphones in the source comparison tool.