If done correctly, increased power handling and greater maximum SPL. If not, phase cancellation, comb-filter effects, and erratic frequency response depending on listening angle relative to the speaker.
When speakers duplicate drivers
What are the effects of duplicating drivers? I'm not talking about the so-called "half" driver where one does, say, both bass and midrange and the other does only bass, I'm talking about straight duplication.
What is the effect on sound? From a technical standpoint, what happens to the incoming signal when it gets split over duplicate drivers?
What is the effect on sound? From a technical standpoint, what happens to the incoming signal when it gets split over duplicate drivers?