if you are talking about the hookup cable within the unit likley doesnt matter at all, but to get all theoretical about it, I would think that same lenghts of different types of cable would like have more of a sonic impact than differening lengths of the same cable. A few months ago I did lots of cable testing, and 10 foot lenghts of four or five different balanced cables yielded different sounding playback, however 10 foot and 30 foot lengths of the same cable didnt really come up with anything that two people could pick out blind with any consistency. Back to the world of practicality, the length of the hook up wire you use in the box probably isnt nearly as important as *where* you dress it inside the box.
dave