What room correction does, and what it doesn't
Every room changes the sound of a speaker, mostly below 300 Hz. Walls and corners reinforce some bass notes and cancel others, so a speaker that measures flat in a lab can sound boomy at 60 Hz and hollow at 120 Hz on your bookshelf.
The One's room correction runs a sweep through each speaker while the app listens from your seat. It measures the actual response at that spot and applies gentle equalization to flatten the bass peaks. It does not try to boost deep nulls, because that only adds distortion, and it leaves everything above 300 Hz alone.
We limited correction to the low end deliberately. Above that range, what the microphone hears is dominated by reflections your ears already know how to ignore. Correcting it makes measurements prettier and music worse.
Run it once when you set up, and again if you move the speakers or rearrange furniture. It takes about 90 seconds per pair.