Depends on the cable. I tried doing this with tec flex and binding my by wire speaker cables together. It sounded muddy when I seprated them it was much better. Now that is speakers I do not know how other cables will react. I woud guess if they are sheilded like audioquest they will be fine, however if they are not like kimber you may get some negitive effects. maybe call the cable manfacture and ask them.
