On the Sophia 2 the resistors are the "fuses", as well as a means of adjusting the speaker response. Did you check the resistors that you took out? If they were original, and both were blow, then likely the tweeters were taken out at the same time. If both are good it seems unlikely that that the tweeters in both speakers were taken out without popping the resistors on at least one of the speakers (they do work well as a fuse, BTDT, and the tweeter was fine). It's also difficult to believe that the speakers could leave the factory with dead tweeters, but things happen. As others have posted, pulling the tweeters at this point and checking for continuity is the first step - after checking the old resistors. Old resistors fried, then tweets are almost assuredly toast.