I have a dedicated listening room in a literal bomb shelter under my pool house (bomb shelter built by prior owner).
Spent far too much time correcting absorption of frequencies, reflections, dispersion, etc.
And far too much money on obscure components.
Sounds sublime.
My wife hates it because there is no talking in the listening room.
Probably helps with dementia because routing of cables was a serious mental exercise.
A bomb shelter becomes a listening studio! How cool is that?