I have had issues as well, but the guideline above does help.

IF no master nothing works. I found that out when I rewired my system after carpetting the room. I had cables mixed up and nothing worked anymore since the master was not connected correctly.

I do have DSP3100 with revivers, but they are all slave (side and rears). So they are setup as Left/slave, Right/slave and typed to 6.

Sold all M equipment