Bi-wireing speakers

I am curious about Bi-wireing. For many years I have been Bi-amping, I recently moved and have no room for my equipment. I have been reading about Bi-wireing on the web and am confused. All the drawing show two sets of cables coming off either side of the Amp, one set going to the low freq. speaker and one set going to the High Freq. speaker. I would think a 300 Watt Amp could blow a tweeter and you would need some kind of crossover unless they are considering and not showing the speakers internal crossover. What would be the advantage of running two sets of cables to the same terminal on a speaker. Being most cables have their own characteristic I would think that can improve the sound if you had a good match.