I had once been told that one should keep the length of the cables equal, for if one cable was much longer than the other that could result in some unpleasant time lag. However I have just read that although electrons do not move at the speed of light, electricity does. So it looks like it's impossible to hear any difference: a 5m distance would amount to a lag of 5/299,792,458 < 2.10^-8 second. That is, the lag would be less than 2 hundredth of millionth of a second.
I don't know if there could be any other consequence...