You know you could just change the way the pulse charges and tweak iy a little bit, thats how i did it. say all your cannons charge at say 1 second, add a .1 second to the next pulse, a .2 to the next and randomize the pulse charging so that all the cannons dont charge up at the same time, that way all cannons will fire at once on the first shot and then they will fire sequentialy after that