Audio sharing not working

Hello, i've recently upgraded and bought multiplicity 4, coming from a nice experience of the 3rd version.
What unfortunate is that i couldn't manage in 1 hour to find a solution, the problem is pretty simple, i need my main PC to send audio to my secondary PC that will be a streaming PC also. I've tried to disable windows firewall completly, tried switching PC's from "primary" and "secondary" and many other try-click's all over, rebooted aswell. Only thing i didn't try yet is completly reinstalling again, but i doubt this will solve the problem. 
Please i would love some help with the issue