Since you have experimented at home, must have swapped and listened to different cables or components to compare, it appears that you have not included any bias controls to these comparisons. Not difficult, certainly no more so than swapping in a sighted comparison. All you need to do is have someone else do it randomly, they record it, cover the cables unless they are already not visible from the listening place, they leave, you listen and guess A bit of statistics, say 20 trials and 15 correct guess is a good indication Or, at least it would show how difficult it is to guess correctly.