the.com/soundstage

means The perceived spatial field created by a sound system — the sense of width, depth, and placement that lets you hear where each instrument or voice sits in the mix.

from Borrowed straight from film and TV production, where a 'soundstage' was (and is) the physical, soundproofed building where scenes were shot and audio recorded cleanly. Audio engineers and audiophiles lifted the term for the illusion of a virtual acoustic space your speakers or headphones conjure — the word crossed over sometime in the mid-20th century as stereo recording matured enough to actually create one.