Speaker cable length

Logic would dictate that if both the left and the right cables are the same in length, regardless of length, and all of the components provide equal balance in volume and tonality, then all things would be the same/equal.

Using one 5' speaker cable and one 15' speaker cable, no matter what, creates a set of different conditions. Now, you may not hear it, but it cannot logically be "balanced". 

You picked good cable with the 4S11 but there is a lot more to it than gauge. At higher frequencies inductance will dominate over resistance. The 4s11 is good in this respect. Worst case use 2 runs to half impedance.  People go gaga over damping factor but cable runs are normally a very small fraction of voice coil resistance and other impedances in the cross over.  Inductance at high frequeny of the cable can be impactful speaker dependent.

An update: The line magnetic is back from being serviced, and I installed NOS 12AX7s and new 6V6 tubes. Equipment has been moved off to the side, replaced by some musical instruments and a more sound baffling absorbing piece of artwork. 

As for the sound, I really can't tell any differences. Maybe a bit less bass with the new Canare cables? Don't know offhand. but the sound is just as amazing as it was before. You can see the results on my virtual system page

https://systems.audiogon.com/systems/9393