I was recently comparing the latest versions of Mumble and TeamSpeak. I configured both programs very carefully, calibrated everything for my audio hardware. I used the Opus codec set to the highest quality level on both. I completely disabled noise / echo / reduction / cancellation on both, and then I did recordings with both. Despite all the careful settings and configurations, the sound from Mumble sounded much like it was coming through a watery pipe, whereas on TeamSpeak it was nice and clear, perhaps even a little nicer sound quality than Skype. Why the difference?