Voice/Video Chat

I have a session zero tonight, and am not sure how we're going to make it happen. A new player is joining the group, and we tried a test to make sure he was connecting fine. He's not. It was detecting his mic as speakers and vice versa, I switched it to legacy and that seemed to correct things on his end, but then everything stopped working on my end. The issue is possibly that he is a Linux user, so is there a known work around for Linux? 

As someone that runs linux, I have had issues with the mic, though never with hearing people through Roll20.  I have to admit that was for a one shot game, so I didn't work at it very hard.  I run all my games through a different chat client.  If it can't be figured out, you could switch to another chat service.  For instance, I have had no problem with Discord.

Discord will be the back up, but it isn't great long term. Not all of the players are using current tech (using dynamic light crashes the game for them), and I'm the only one with a dual screen. It's hard to sacrifice screen space for a separate video chat and the extra stress on an old processor creates more game delays. Would really like to be able to streamline this. 

I suppose that is true.  I don't use video, so it doesn't matter to me if Discord isn't visible.

Something nice about the Discord alternative, if they have a Tablet or a Smartphone, discord runs nicely on that. Thus saving their computer and main screen for 100% just roll20 loading.