Question

I taught my question was clear that I have 2-StudioLive 32.4.2AI not the RM series.
Unless you are telling me that it can only be done with an RM

Answer 1

Sorry, it was not clear to me. Two SL boards are cascaded by a single firewire cable and here you can read everything about it:http://support.presonus.com/hc/en-us/articles/210048283-StudioLive-Ai-Mixers-Cascading-StudioLive-Ai-mixers-and-Troubleshooting