Techflex on speaker cable: sonic impact?

I put techflex on the pair of cables I run to the rear of my home theater. I could have sworn that after that, the sound became a bit muffled. I'm not losing sleep over the sound of the rears of my home theatre but I would like to know for future especially as regards my home audio system - can I expect sonic degradation by covering the cable with techflex?

A complication: I used the techflex to cover a pair of 16 gauge cables, that were loose and separate, but now very tightly wound next to each other. Perhaps that is the issue rather than the techflex per se?

Bottom line: can you share any experiences or word-of-mouth regarding use of techflex and changes in sound quality?

Thanks,
Art