recommendation for speaker wire to soften the highs if possible

I love reading the responses to these sorts of questions. Every answer a different notion. Try this try that, no it's your frammims.. Sorry you need a new _______. (twenty different things)If you do them all, you would have spent the equivalent of a down payment on a new home. And still have no answer. The pitfalls of audio madness.

Some are actually true and helpful. Hard to weed through it all. 

Personally, I don’t believe a cable can effect the frequency response of a system, nor act like tone controls.

When someone describes a cable as “taming the high end” to me it seems like he’s describing a room interaction problem with the speakers, a speaker shouldn’t naturally sound shrill unless it’s badly designed or is having some serious first point reflection issues.

So basically, if you’re to believe these people, they are claiming that their cables are lowering the 2-5khz range by a few dB.

I’m not a electrical or sound engineer or a scientist of any kind, but that just doesn’t seem logical or scientific to me. 

Cables can lack bass, exhibit midrange suckout and/or lack sparkle and air and/or other frequency related anomalies. I attribute that to cables affecting the frequency response. I readily admit I haven’t checked cables with an oscilloscope. Is that wrong?

d2girls, cable has inductance, capacitance, and resistance. These are the 3 qualities used in electrical filters, it's what speaker crossovers use to separate frequencies, so unfortunately cables are very capable of distorting sound. That's why I use Duelund exclusively for interconnects. Western Electric used to be AT&Ts sole source for cables, and when wires were necessary for telephone communications people spoke to and fully understood each other from coast to cost using Western Electric (W.E.) designed cables, and Duelund has slightly improved upon it, likely due to improvements in the purity of the metals used, but regardless, they are the most neutral cables I have found. For speakers I am using W.E. because it's less expensive, and while I haven't A/B'd them yet, I have used Goertz for decades, nothing other than W.E. has been listenable. Mind you I have crazy revealing equipment and I run a full range driver, so what comes out of my amplifier does not go through a crossover, and it's amazing how much of a difference that makes! I have reworked many crossovers using V-Caps to by-pass larger caps, and replacing crappy resistors with Mills non-inductive wire wound resistors, but regardless how good the components are, you are still filtering the sound and trying to match drivers. Nothing beats a good full range driver IMO. Frankly Don Sachs talked me into trying it, he made my preamp so I knew that he knows what is what where sound is concerned. Before I bought the preamp we spoke extensively about component quality and such because I wanted to be sure that I wasn't going to regret buying his DS2 preamp... Anyway, cables absolutely impact the sound, though if your equipment is sufficiently colored, it's possible to mask that, at least to some extent. The more neutral your gear, the more obvious the differences between colored and neutral components.