Short answer
Both are portable players, $3899 against $2959.
On raw power they are level: each reaches 100 dB on 566 of the 567 non-electrostatic models here.
| Specification | Luxury & Precision P6 Pro | Shanling M9 Plus |
|---|---|---|
| Power into 32Ω | 180 mW | 520 mW |
| Power into 150Ω | 39 mW | 111 mW |
| Power into 300Ω | 20 mW | 55 mW |
| Power into 600Ω | 10.0 mW | 28 mW |
| Output impedance | 0.2 Ω | 1 Ω |
| Output noise | not published | not published |
| Price | $3899 | $2959 |
| Headphones it reaches 100 dB on out of 567 | 566 | 566 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Balanced | Luxury & Precision P6 Pro | Shanling M9 Plus |
|---|---|---|
| Socket | 4.4mm | 4.4mm |
| Power into 32Ω | 700 mW | 1.1 W |
| Power into 300Ω | 80 mW | 120 mW derived |
| Output impedance | 0.4 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 Luxury & Precision P6 Pro on 566. Derived figures are worked out from the loads the maker did publish.
| Load | Luxury & Precision P6 Pro | Shanling M9 Plus |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Published | Derived |
| 600 Ω | Derived | Derived |
Both makers publish a power rating. Luxury & Precision P6 Pro publishes at 32 Ω and at 300 Ω; Shanling M9 Plus at 32 Ω. The other rows are worked out from those.
So the two columns are not equally firm row by row: at 300 Ω only the Luxury & Precision P6 Pro figure is the maker’s own. On those rows the derived number is the one to doubt first.
On power they are interchangeable across this whole database: there is no headphone here that one reaches 100 dB on and the other does not.
15 headphones are left alone by the Luxury & Precision P6 Pro under the one-eighth rule but coloured by the Shanling M9 Plus (64 Audio Nio, 64 Audio Volur, Campfire Audio Andromeda 2023, 12 more).
566 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 HiFiMAN Susvara: Shanling M9 Plus has +7 dB of headroom there against +3 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 Luxury & Precision P6 Pro and Shanling M9 Plus because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Luxury & Precision P6 Pro headroom | Shanling M9 Plus headroom | Luxury & Precision P6 Pro hiss | Shanling M9 Plus hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +37 dB | +36 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +17 dB | +16 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +20 dB | +25 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +16 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 | +9 dB | +13 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +5 dB | +9 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +3 dB | +7 dB | not published | not published |
The Luxury & Precision P6 Pro costs $940 more than the Shanling M9 Plus. Out of the 567 models here, that difference buys 15 more models left alone under the one-eighth rule.
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: Luxury & Precision P6 Pro and Shanling M9 Plus.