Comment by matclayton

Depends on if you are on free or Pro account as the uploader, if you are on Pro we up the bitrate substantially. Beyond this, it also depends on the device the user is listening on, we'll switch over to Opus when possible, which makes a big difference. If you want to max out the quality I would recommend you get Pro and ensure you listen on Chrome (or mobile apps). We'll do up to 320k on aac and 192k on opus. On Live we do something similar and last time I checked we did substantially higher rates than twitch on audio, but lower bitrates on the video.