No one actually knows how to lculate what speaker cable they need

@b4icu
I believe that the current retail for a set of M1's is little over US $ 100k, however the Pendragons were sold for about US 175k. Bargaining on this kind of equipment is not easy. Even where I live (Indonesia) where indeed you are expected to bargain, however the moment you go for so called "high-end" there is not much bargaining anymore. You may get a good discount on a Toyota, but will pay the full price for a Lamborghini. As mentioned before, I'm happy with the sound I'm getting. Unfortunately current main issue is my room acoustics, I have moved house some time ago, and haven't tuned my new room yet. Major/alarming difference compared to my previous room. But a bit off-topic to elaborate about that on this thread. 

@b4icu
Thank you sir, I'm not sure I buy what you're selling..........for free as you say:), but I may look for some 0 awg and give it a try. It could prove interesting..............It's obvious that I have a WAY smaller budget than many here, and my system reflects that. That said, I'm always looking for ways to improve what I hear.........If the "0" gauge wire doesn't do anything for my system, I can always use it to tow a car or something :)

Mr.  shadowcat2016
Please no "Sir". 

Before you spend some money on a 0 AWG speaker cable, I would recommend you an experiment, that might cost you little of nothing.
Get your amp and speakers closer, to shorten the length from 15' to 7-8'. Try to do (with great care and caution) a connection with two jump start cables, of 0 AWG (the heavy duty type).
If that works for you, you may try to get a set for a good price.
I can recommend you my solution.

b4icu..........thank you again. I did have my amp between the speakers until recently, with shorter cables. The spot was inconvenient, but I understand your point, shorter is better.......and less expensive :)............Most here seem to be male, I made that assumption in your case.............My apologies.