Short answer
Both are portable players, $1999 against $2959.
The Shanling M9 Plus reaches 100 dB on 566 of the 567 models here, the Cayin N7 on 565.
| Specification | Cayin N7 | Shanling M9 Plus |
|---|---|---|
| Power into 32Ω | 250 mW | 520 mW |
| Power into 150Ω | 53 mW | 111 mW |
| Power into 300Ω | 27 mW | 55 mW |
| Power into 600Ω | 13 mW | 28 mW |
| Output impedance | 0.6 Ω | 1 Ω |
| Output noise | not published | not published |
| Price | $1999 | $2959 |
| Headphones it reaches 100 dB on out of 567 | 565 | 566 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Balanced | Cayin N7 | Shanling M9 Plus |
|---|---|---|
| Socket | 4.4mm | 4.4mm |
| Power into 32Ω | 500 mW | 1.1 W |
| Power into 300Ω | 53 mW derived | 120 mW derived |
| Output impedance | 1.2 Ω | 1 Ω |
| Output noise | not published | not published |
| Headphones it reaches 100 dB on out of 567 | 566 | 567 |
Through the balanced sockets the Shanling M9 Plus reaches 100 dB on 567 of the 567 models here and the Cayin N7 on 566. Derived figures are worked out from the loads the maker did publish.
| Load | Cayin N7 | Shanling M9 Plus |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Derived |
| 600 Ω | Derived | Derived |
Both makers publish a power rating. Cayin N7 publishes at 32 Ω; Shanling M9 Plus at 32 Ω. The other rows are worked out from those.
The two publish at the same loads, which is the one case where the rows of this table can be read straight across.
1 headphone reaches 100 dB on the Shanling M9 Plus but not on the Cayin N7 — Moondrop PARA.
14 headphones are left alone by the Cayin N7 under the one-eighth rule but coloured by the Shanling M9 Plus (64 Audio Nio, 64 Audio Volur, Campfire Audio Andromeda 2023, 11 more).
565 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: Shanling M9 Plus has +13 dB of headroom there against +10 dB. 3 dB is about 2.1 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Cayin N7 and Shanling M9 Plus because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Cayin N7 headroom | Shanling M9 Plus headroom | Cayin N7 hiss | Shanling M9 Plus hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +32 dB | +36 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +12 dB | +16 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +22 dB | +25 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +17 dB | +20 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +14 dB | +17 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +10 dB | +13 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +6 dB | +9 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +4 dB | +7 dB | not published | not published |
The Shanling M9 Plus costs $960 more than the Cayin N7. Out of the 567 models here, that difference buys 1 more model driven to 100 dB.
It does not run one way only: the cheaper Cayin N7 leaves 14 models alone under the one-eighth rule that the Shanling M9 Plus does not, which is the part worth checking against your own headphones before paying the difference.
Only published figures count here; blank axes are counted separately.
Each in full: Cayin N7 and Shanling M9 Plus.