Mario Party 6 netplay issue

[Flashy]

So I was trying out Mario Party 6 with my friend over netplay. It seemed to work fine (no desync or input lag) except it didn't ran smoothly. FPS was low and cause of that the sounds of the game were horrible and we needed to mute the game. We both have a high-end pc so that is not the problem. Also we were testing this out on Dolphin 5.0-321 build. Any suggestions? Preferred settings? Simply use another dolphin build? Thanks.