Anti-Cable High Frequency Performance

I've just installed a set of anti-cables in my bi-wired system with Magnepan 3.6 speakers. I find the bass and mid-range nice and tight and the overall sound very balanced, smooth, and natural. The soundstage is very good.

But I notice that the high end is not as extended as my previous cables (good quality oxygen free heavy gauge copper strand). There's less detail in the upper end.

I did twist the anti-cables as directed in the instructions to get as much high end performance as possible.

I like the natural sound but I miss the high end definition.

Has anyone else had a similar experience?

Or, does anyone have any advice about alternative cables at the same price?

I should say that I am very impressed with the overall quality of the sound. This is not an anti-anti-cable post. Just trying to tweak it some more.