Wireworld Gold Eclipse speaker cable

Hi, does any of you have experience with the Wireworld Gold Eclipse speaker cable? In my system the sound becomes a bit thin (as if a part of the harmonic richness is missing). The treble especially suffers from this thinning out. The most important virtue of the Gold Eclipse is it's detail resolving capability.
Btw, I'm using JMF power amplifiers and Soundlab A-1's.

Chris