Considering A SS amplifier

@neonknight 
..I seem to recall that long speaker wire is more preferable than long interconnect runs...

XLR interconnect cables are specifically designed for long runs. The test was to validate it so you could rectify the situation, "loss".    

Would you entertain "speaker wire length advice" from the CEO of PS Audio, the guy who partnered with Bascom H. King to design and manufacture your BHK amplifier?

Video:
https://youtu.be/Xd8JYfiKp3c

When I had speakers on either side of our fireplace, I placed the amp in the basement below and between them.  Then I drilled holes to run cabling down to and back from the amp.  Worked very nicely.

From everything that I have read (or mostly) it is preferable to have long IC and short speaker cables. Having just gone to mono blocks I had two sets of custom cables made up 5' length as my speakers require two cables rather than a bi-wire as the terminals are too far apart (40") to do successfully with a bi-wire cable. When I swapped my original set-up cables (10') for these there was quite a difference, no longer laid back, but in your face detail both hf and sub...a thought 

neonknight with that configuration, maybe you need a new house more than you need a new amp? 

@neonknight replace the wireworld cables with analysis plus, I find that I don't like the wireworld house sound.