I cannot find the posts right now. Someone with new 20.7 had a strange problem, Seemed the low freq portion of crossover was connected to the mids panel and vice versa. Magnepan replaced the speakers. This was recently posted.
Naturally I was interested and remembered it. but what site???
The main point to me was Magnepan investigated it and sent a new replacement pair once the issue was verified (probably by the dealer, same as mine was investigated by the dealer techs.)