can't stand the silence!

Minbari weapons port seem to be very linear and unidirectional, well they do have them 50+ meter cannon ports that extend out from the main body, yet time and time again we see them become highly versatile in the direction they shoot in. Why is that? How is that possible? If the energy from the cannon is released and the ports lead that energy out for even that 50 meters of it how is it that they would bend that beam in different direction?