Hard to figure out what you’re trying to accomplish. Are you using x11? X11 doesn’t touch audio, so x11 forwarding itself won’t work, you’ll have to tunnel the whole stream. And if you get that to work, you’ll have reinvented https streaming. It’s so much simpler to just use a local client to connect to remote resources, or make the stream available in a protocol meant for streaming media, like rtsp or das.