I have searched the forums and internet and still have no simple answer. I have a Backline 600 head at 300w 4ohm with a GLX 4x10 cab thats 400w 8ohm. So right now I am only getting about 150w correct? Was planning on adding a 1x15 8ohm. Now when I add that would the head then put 150w to each cab or 300w to each cab?