Speakers being out of phase was brought up earlier. I think the emphasis was on individual drivers within one or both of the speakers being wired out of phase.
Sorry if this has already been brought up, but it is a 10 second test. On ONE of the speakers ONLY, I would connect the red (positive) speaker wire to the black (negative) speaker terminal and the black (negative) speaker wire to the red (positive) speaker terminal. Just to see if it helps in case one of the whole speakers was wired out of phase.
Regarding Blue Jeans speaker wire, they predominately use Belden and Canare speaker wire. I have both. The Canare 4s11 is considered very good by many. I did not like the Belden quite as much but many like and use it without problem.