I'm experiencing very crackly audio (hard to hear what is happening) when using headphones and only when the controller is on WiFi (sound from the Chromecast is fine and sound from the 3.5mm jack on the headphones is fine when the controller is connected to my phone by USB C).
I have tried on two different internet connections, one of them with ridiculously good WiFi that nobody else was using and insanely low latency (with plenty of bandwidth) and another less good, and with two sets of headphones.
I have reported it via feedback, but not got any sort of reply or acknowledgement.
So, I spoke to support again. They had said that I would get a reply from someone higher up in the support team, and I got an email, referencing my case, asking me to submit feedback (it wasn't even clear if it was feedback about the handling of the case, or feedback about the Stadia experience in the app, or what, the email didn't even make sense), so I wanted to make sure that wasn't them closing the case.
The agent this time said that this is a know firmware issue, and that I would have to wait for a firmware update to fix it, but that there is no time frame for that yet.
Edit: I was annoyed whne I wrote the next bit. I'm still experiencing unbelievably bad customer service from Google, but I don't really think any differently about the concept/theoretical potential of Stadia. I do however worry that it may never succeed because of the terrible customer service Google has meaning that they can never get enough people on board. I've been waiting weeks for a related issue to be solved by Google customer supoort. To be absolutely honest, I am losing faith in the whole idea of Stadia, or Google's ability to deliver it anyway, and am not planning to buy any more games right now. I might see if I can get a refund for the ones I have purchased if this doesn't get sorted soon, since I haven't been able to meaningfully play anything on Stadia - all of my play time has been trying combinations of things to see whether it works OK. I can't currently play in an even vaguely acceptable way on any platform except for my desktop computer, but I can play all of the games on Stadia on that anyway, and buy them for less off of Steam, so I have no interest in doing that and there is no point to Stadia right now for me. This audio issue isn't the only issue I have - I have terrible input lag on my Chromebook, even when connected to a ridiculously high bandwidth, low latency, highly reliable internet connection at work (but same at home too).
If this can't work for someone like me with multiple bits of Google hardware the best internet connection you could really wish for for this (well, many people have more bandwidth, but there is plenty of bandwidth and the more important properties are the ridiculously low latency and basically non-existent packet loss, and the amazing WiFi connection, all carefully monitored to check for issues, and basically unused by anything else when I am trying Stadia), I don't have faith Google will ever get it to work satisfactorily. Maybe someone else will get game streaming working better, but Google just doesn't have the culture required to release reliable stuff and make it work properly, or the will to apply it to this anyway, I don't think. It is a shame, because I think they probably have the best network of anyone to deliver this kind of thing.
This is affecting me as well, on both TV+CC and Chrome Browser via MBP. I tried multiple pairs of headphones, I tried a factory reset of the controller, and I tried connecting to 2.4 GHz Wifi. None of these measures addressed the issue. I've sent feedback in the app.
I have exactly the same issue. I’ve avoided for a couple of weeks by just playing on TV but have now purchased Boarderlands 3 and want to play with friends so I need the heads set to work. Has anyone found a fix or confirmed it is hardware?
@Starbuck Support told me that it is firmware, so should be fixable with a firmware update for the controllers, but it is not software, so changing your setup likely won't help. No ETA as far as I know on the firmware fix.