There is a word that describes a person who is particularly fond of recorded music and demands only the best quality sound reproduction equipment available, the name given to this person is audiophile. The enjoyment of music faithfully reproduced on quality equipment does not commit you to a room filled with large loudspeakers and miles of trailing wire but it is certain that the best sound comes from equipment that is not all contained in one unit, but carefully assembled from a wide range of combinations.
The term for two or three or more pieces of hi-fi equipment that are connected together to form one system is separates. These items can be made by one manufacturer or in many cases from different manufacturers enabling the very best combination of equipment to be brought together. This makes it easier to upgrade any one piece of equipment at a later date should new products become available or when the budget allows.