Audio Systems consist of electrical circuits (amplifier, player), mechanical circuits (loudspeaker-membrane) and acoustical circuits (air, room acoustics). All

Audio Systems consist of electrical circuits (amplifier, player), mechanical circuits (loudspeaker-membrane) and acoustical circuits (air, room acoustics). All these parts can be modeled as circuits that directly interact with each other. You can actually calculate the electrical properties of the mechano-acoustical loudspeaker+room or the acoustical properties of the electro-mechanical loudspeaker+amp. This is extremely helpful when designing loudspeakers since you can see the electrical, mechanical and acoustical properties all in one notation.