"Let’s start with the simplest of systems, a two-channel music system. Typically, the components are placed on top of each other or stacked on the shelves of an audio component rack. This is perfectly fine as long as there is enough ventilation between the components – many components have ventilation slats on the top of the case. In an audio system it is best to use cables as short as possible, especially those that transmit analog signals. In most cases cable lengths of 3 to 6 feet will be sufficient between components. This will minimize the effects of RF and EMI interference and result in an improved audio performance.
Speaker cables will be dictated by how far apart they are, but again the lengths should be kept to a minimum. I like to use twist ties (which new cables are often wrapped with) to keep the cables tidy behind the rack and to prevent them from sticking out at the sides of the components. This method works perfectly well for digital cables, although audio/video purists will argue that coiling analog cables is far from ideal because it creates inductance in the cable (especially in power cords), which can deteriorate audio and video performance."