For my system, it's everything and anything I play, whether its LP's on either of two turntables or digital music through streaming services or my own library.
The effect is there due to the room acoustics and speaker placement. It's incredible, and the only variation is with the dimensions of the soundstage. With digital, it's pretty much a fixed presentation. With analog, it can vary depending upon choices of cartridge and phono amp settings, though never is it "connected to the speakers."