OK guys, thanks for the help so far!!!
I decided to star with the LF1 first (2 RLp 15s) in a line array, I will listen to it first before cutting the other side. The plan is to build a box for the other two subs and move it around the room to see where the best sounding spot its going to be.
Should I build the box for one 15 o I need to built it for the two for testing?