Is it appropriate to route the signal from the first box directly to the second box? Does the signal need amplification at this point? What sort of amplification does that signal need once it has passed through two boxes? Could the amp that is driving the monitors be underpowered? I'm grasping at straws here.
Yes, it's appropriate to route the signal from the first box directly to the second box. People do this all the time, and you shouldn't need any sort of amplification or other signal alterations between the two boxes.
The only thing left to consider is whether it has to do with the adapters I am using for the mono cables. I am using two 1/8" to 1/4" mono adapters becuase two of the cables are 1/8" on one end and 1/4" on the other.
Oh, you should definitely try other cables.
