Currently
Office: 2-channel & headphone vinyl/streaming rig
Family Room: 2.1 combo HT/music
Basement: 5.2.4 Home Theatre w/ in-wall/in-ceiling speakers and in-room subs
Master Bedroom: Naim Muso used for music & as a soundbar
Garage: obsolete pioneer receiver with old bookshelves I upgraded from elsewhere
So I’d say 5, but some may say only 1. The office system is all mine and my favorite… the rest are compromises to be used by the whole family, with the family room system easily getting the most use. Hope to add some outdoor speakers for the patio this Spring/Summer. My wife couldn’t care less and is just as happy listening to an Alexa in the kitchen as any of the much better sounding systems… but she lets me have my fun.