It does depend on the specifics. A system with just a CD player driving powered loudspeakers presents a vastly smaller reflective surface area than say this. Placing equipment between the loudspeakers just isn't a problem in some situation, in others it is.
If we are going to talk about the ideal, then ideally your source components and electronics (power amps excepted) shouldn't be in the listening room, but in an adjacent dedicated, custom designed equipment room.
If we are going to talk about the ideal, then ideally your source components and electronics (power amps excepted) shouldn't be in the listening room, but in an adjacent dedicated, custom designed equipment room.