So, what is the goal of the speaker???
Speaker is a transducer. It converts electrical energy into mechanical energy. My point is: we can not say that electrical energy is the same as mechanical energy or that there is only one way to convert one into another. That's why sinergy is so important in a system.
Anyways the main point is that anyone can listen to recorded music as a hobby, it's a subjective hobby, but if one prefers technology as a hobby, or both, he needs specific knowledge in some areas, it's an objective hobby.