This is why cable companies give you 30 to 45 days to live with them. If you don't like what they are bring out of your system just return them. All cables are system dependent.
Comparing Speaker Cables
I have accumulated several pairs of speaker cables that I have never tried to do careful A/B comparisons of because the time it takes to swap them is longer than my audio memory. But my speakers are bi-wired and it occurred to me that I could hook two different cables up and then only swap them at the amp which would be much faster. Is there any sonic downside to having a pair of unconnected cables hanging off one of the sets of inputs while the second set is connected to the amp?