Yamaha DTXpress/DTXplorer/DTXtreme

I have a DTXpress III Spec.Ed kit. I also have an Yamaha MG82fx 
non powered mixer, Yamaha MSR100 powered speaker, and the Yamaha MS50DR 
Monitor system. I am seeking the best way to connect all this together 
for optimum efficiency. I currently use the MSR100 facing out to my 
listeners using the control room outputs on the mixer. Last I have an 
mp3 player going into the mixer too. I find that the MSR100 can't 
tolerate much bass so turn it completely off on the back panel of the 
MSR100. I guess I am just looking for some other workable options. 
Thanks everyone!!!