One rich fool alays there to buy these, then they HAVE to sound better in order to justify the mistake!
I use medical cable which is probably also used elswhere. Nothing fancy, but a well screened mains cable I discovered when using and servicing ECG & EEG equipment many years ago. The addition of a few ferrite rings and beads sorts out many problems. One factor is earthing and determining as to which end to earth the screen as that is random and does indeed make a large difference. Well, here is another hornets nest I have dropped myself into...