Hi-fi and Sound system

Hi-fi noun - The reproduction of sound with little or no distortion.

Sound system and hi-fi are semantically related in stereo system topic. In some cases you can use "Sound system" instead a noun phrase "Hi-fi", when it comes to topics like machine for playing record albums.

Sound system noun - A system of electronic equipment for recording or reproducing sound.

Hi-fi and sound system are semantically related in stereo system topic. You can use "Hi-fi" instead a noun phrase "Sound system", if it concerns topics such as machine for playing record albums.