The Cerious Technologies Graphene Extreme cables are very good sounding and don't here toward brightness. Their Matrix cables are much better, but cost almost 3 times as much. I have the CTGE cables which tended to tone my VMPS RM40 speakers with 40" of ribbons per speaker down and give them more of an organic sound with better balance. They go for $640 for an 8 ft. pair, but you could find them used for around $350-400 a pair.
Bob