Well... guess I have to jump in the rabbit hole of speaker cables... lol

denon cd player
Mac C-41 pre
no amp at the moment

was a mac 7100 she couldn’t run the 10t’s

Have a Parasound A 21 coming in a month or so.

Cables are not your problem. Sounds like problem(s) with upstream components to me. That Mac was likely the culprit.

FWIW, I agree with Stevechamp. Cables are not your problem, and certainly the Belden 10 ga is not a problem which another cable is likely to solve. If anything I suspect that other cables will exacerbate the problem. I have been using the Belden for some years now in preference to several other high end cables, they are not 'bright'. Be careful in matching an amp to your speakers that you do not get an amp which might just aggrevate your perception of brightness. 

If I were you, I would insure that I had maximized all set up possibilities before I concluded that your problem cannot be solved without getting different stuff. Been there. If I had taken my own advise I'd have saved a ton of dough going thru the component merry-go-round.

captbeaver

It’s not your Belden cables.   They are “industry standard” cables long used in the pro realm for many of your favorite recordings.  They would not be used if they had some weird defect like “raspy highs” and all the recordings using those cables would have “raspy highs.”  But the don’t.
You can look up measurements for those exact cables (e.g. on audiohilics) and see they measure superbly.

FWIW I use the Belden 10awg speaker cables (from BJ Cables) and my system certainly doesn’t have raspy highs.  I’d hate that.

Beware of “friends” bearing expensive cables.  ;-)

Look elsewhere in your system including room acoustics, speaker positioning.  Remember that different speakers interact in different ways with a room/listener position.