Need cable advice tome reduces mids

@dtapo so few thoughts on this…

1. Your earlier post on new amp causing fatigue. Amplification in question is Denafrips, correct?
2. Your Canare cables are neutral. They don’t emphasize any particular bandwidth or frequency range. They’re not the best cables in the world but by no means are they contributing to this

3. You have kit speakers that you built, correct?

The fatigue you’re talking about in your posts is usually a result of overemphasized presence region. It’s not just mids. It’s a hump in that frequency region and the only way to get rid of it is to remove the component that’s causing it. Your amp/preamp/speaker combo is not a good match. 
My recommendation would be to dump the amp and potentially even change the speakers. No cable will fix this issue. I would also not entertain band-aid type solution such as an equalizer to remediate this problem. If you continue to use this system you might even end up damaging your hearing. 
 

You have a Hegel amp that without the same system doesn’t cause this problem and if that’s the case it just proves what I’m saying here is correct. 
 

That’s all I got for now. You decide. 

 “within” the same system is what I meant to say…autocorrect had other thoughts obviously…

audphile1  I believe you are correct, that it's the synergy between these components causing the problem. I was hoping that there would be a solution and I could salvage the system. In my listening sessions, the peaks never go above 75dB, so it's not a "loudness" problem.

It very well could be a synergy issue. But first, what is the size and layout of your room? Are you using any wall treatments to absorb standing waves? I'm referring to mid to high frequencies.

It’s the speakers that are at fault. Peak in the midrange. Use DSP to correct this. Don’t bother with an analog equalizer. These add phase distortion.