Uh, oh.... This was sort of discussed elsewhere here and I was basically called a crazy person for saying that there would be any interference running power and network in the same holes. Speaker wires aren't protected from interference like network cables (cat5, cat6). So I will use those dreaded words... "Best Practice" would be to put them in a separate hole.
However, I bet that a number of people have them run side by side out there, at least through one common hole in a stud, joist, or whatever, without any noticeable issue. The problem is that it is hard to change later.
