You need a direct box - two direct boxes actually, L & R, so that you will not have an impedance mismatch.
TY
clarification:
So the purpose of using DI on this is to create an unbalanced signal out of balanced input from the mixer is that correct?
Or maybe my questions really are...
What is the impedance of the input from the mixer and how does it compare with the impedance of the mic input on the powered speaker?
How does the DI match the impedances of the units?
Are there switches on DIs to do this or is it part of its primary functions?