So just like a normal speaker wire between the 2?
Correct, but I'm still very interested in hearing the results of the other tests I mentioned.
Whilst I didn’t try the cheater plug specially, the fact that the Hum-X didn’t work leads me to believe the cheater wouldn’t have any effect.
Sorry, I can't agree with that @kingbr - two different concepts. If it were me, I'd still try the cheater plug. You really have to eliminate all options here. I think they're only like $3.