I don't know what "traditional stereo" means to you.

My music is stored on a computer sitting near a TV and a Yamaha receiver, which runs five main speakers and two subwoofers.

There's a powered speaker set hooked to a Chromecast audio in another room, and a cheap old laptop running an old Yamaha receiver with 2 mains and a sub in the living room.

forked-daapd (you'll want the current version out of github) runs on the main computer and has a web interface. It can talk to the Chromecast and the laptop and the main receiver to send the same audio to all of them. Delays can be adjusted.

I hardly ever do that. Instead, I call up music in whatever room I'm in.