Connect few group channels to master channel group

Hello. How i can make this?

Speaker<-- Master Channel <------------ Group Wav
           Group  (MCG)     \         /
                             Group A <-------- Group Mic          

1. Group Wav to MCG and to Group A
2. Group Mic  to Group A
3. Group A to MCG

You should be able to set most of that up with simply creating ChannelGroups and using addGroup. The second output from Group Wav to Group A will require manually adding a connection between the head DSP of Group Wav and the tail DSP of Group A.

Have you seen the dsp_effect_per_speaker example we ship? It demonstrates how to do these kind of connections.