I read many times about monitors, "delivered as matched pair", what is that supposed to mean? that every pair of same kind of monitor will sound a little different?!
Well, Vadim, I just gave a gal a "matched" pair of saphires and that means they are close to the same weight, they are the same size, and they have the same luster.
I'm guessing that a matched pair of monitors will have exact tolerances, output capacity, and, of course, they do look identical.
I don't know if the term "matched pair" applies to both passive and active monitors.
But, for a quicker and probably more accurate answer, you can google the question and get some kind of profound answer.