Speaker Cables

I was trying to make an exaggerated point

It sounds more like you were perpetuating misinformation shady cable manufacturers are using to sell their wares by attempting to sound knowledgeable.

@jjss49 I second twoleftears suggestion of Duelund for your internal wiring. Check out the PartsConnexion site for various gauges. 

@jjss49 
+1 @pesky_wabbit mentioned Partsconnexion, another good option. I had forgotten to mention them as I have not bought internal wire from them in a while. Also It looks like they are selling the Cardas black/red wire again, including Ultra Pure Copper, Multi-Stranded Litz Hook-up Wire if compelled.                                                                                                             

While you are at it, I also recommend you change your crossover capacitors to the following:

https://www.partsconnexion.com/Jantzen-silver-cap.html

These are at a very nice sweet spot of price per performance ratio. There are many more better film caps but they are also much more expensive.

Changing the capacitors becomes a must, if you see any bipolar electrolytic capacitors (note that I said BIPOLAR) in your old crossovers. It is very unlikely that you will ever see unipolar electrolytics in a crossover but bipolars are possible. All electrolytics, unipolar or bipolar, are a ticking time bomb. Spendors are usually great quality but just check if they have any caps which may need replacing.

ProAc speakers have a reputation for being relatively even in response. If you'd like to maintain that honesty I would contact Audio Envy and have them build you a bi-connector set. I believe they're upgrading their SP9 orders to SP11's. The set that they sent me was phenomenal and more even in  response to the point that I no longer used my dirac correction and when I did an impedance sweep it was notably smoother.