I wish to add a late note to this discussion, because in 2016, many top bookshelf and many floorstanding speakers are using ribbons. The modern version have tamed the electronic tweeter to make it desired in high end speakers. On the lower end is HTD which uses ribbons in their top line. I have the Swans M1 and the M1B that I built, and they have replaced all other speakers in my home, and always will. I've sold some better Monitor Audio and Polk bookshelf speakers, and gave away some mid-priced Polk speakers I never used. However, my main fronts on my surround system are Paradigm Monitor 11s because the size of the drivers do count for movies.
