Short answer
Both are desktop amplifiers, $660 against $629.
On raw power they are level: each reaches 100 dB on 567 of the 567 non-electrostatic models here.
| Specification | Grace Design m900 | Lake People G111 Mk II |
|---|---|---|
| Power into 32Ω | 1.0 W | 1.4 W |
| Power into 150Ω | 228 mW | 1.4 W |
| Power into 300Ω | 115 mW | 1.1 W |
| Power into 600Ω | 57 mW | 600 mW |
| Output impedance | 0.08 Ω | 0.125 Ω |
| Output noise | 5.01 µV | 6.9 µV |
| Price | $660 | $629 |
| Headphones it reaches 100 dB on out of 567 | 567 | 567 |
| Load | Grace Design m900 | Lake People G111 Mk II |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Published | Published |
| 600 Ω | Published | Published |
Both makers publish a power rating. Grace Design m900 publishes at 32 Ω, at 300 Ω and at 600 Ω; Lake People G111 Mk II at 32 Ω, at 300 Ω and at 600 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.
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.
55 headphones stay below the audible-hiss threshold on the Grace Design m900 but cross it on the Lake People G111 Mk II (64 Audio Aspire 1, 64 Audio Ocean, 64 Audio Volur, 52 more).
567 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: Lake People G111 Mk II has +27 dB of headroom there against +17 dB. 10 dB is about 9.9 times the power, which matters for peaks rather than for how loud the music sits.
Hiss below about 20 dB SPL is inaudible in a quiet room.
| Headphone | Impedance | Needs | Grace Design m900 headroom | Lake People G111 Mk II headroom | Grace Design m900 hiss | Lake People G111 Mk II hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +44 dB | +40 dB | 28 dB | 31 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +24 dB | +20 dB | 8 dB | 11 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +28 dB | +34 dB | 7 dB | 9 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +23 dB | +32 dB | 2 dB | 5 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +22 dB | +22 dB | 1 dB | 4 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +17 dB | +27 dB | -5 dB | -2 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +12 dB | +22 dB | -9 dB | -6 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | +11 dB | +16 dB | -11 dB | -8 dB |
The Grace Design m900 costs $31 more than the Lake People G111 Mk II. Out of the 567 models here, that difference buys 55 more models kept below the audible-hiss threshold.
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: Grace Design m900 and Lake People G111 Mk II.