I have a Presonus Studio 192, a Digimax DP88, and a Digimax FS8. I'm running 8 drum mics on the DP88 and 3 mics on the 192. I need a stereo mix of the drum mics I can send to my ********* P16i headphone monitor system along with the outputs of the remaining channels of the 192 and all of the channels of the FS8.