Coupling Banana Plugs

Good point. I used some clear thick spiral wrap around the metal.

For your rear speakers, there's really no reason to use expensive cables. A spool of Audioquest or Monster should be all you need. Use anything more than that, and I don't think you'll be able to hear a difference.

+1 zd542

Zd542, Swampwalker, thank you for your comments.
I had about 25 feet of Kimber 8TC and found another 18 footer used. This second set replaced a cheaper 20 foot pair.
With the cable now all the same, I found that it did increase the output and the sound quality.