4 matching transformers:

    2 - matching transformers 
                (male 1/4" to mail   xlr)
    2 - matching transformers 
                (male 1/4" to female xlr)

4  mic cables (xlr male to xlr female)

1  speakon nuetric cable
 
 

1.  connect two transformers in the PRE OUT left and right jacks on the back of the SD8, then,  connect mic cable from the transformers to  the back panel of the MP418sp (INPUT       internal  and external xlr connectors)

2.   connect from the MP418sp from the HIGH PASS outputs, 2 mic cable back to the SD8, use matching transformers to connect to the 1/4" inputs on the SD8 labeled  AMP IN L & R.
 

3.  connect a speakon cable from the active sub woofer to the passive sub woofer .