Okay so I just went a private general tracker and looked up an av1 movie. It is a 2014 feature film encoded by the WhiskyJack group (the better trackers don’t allow AV1 content yet). For this film, the audio codec is Opus. I looked in the nfo and for the audio file, it says that they are using Opus 5.1 with a 32 bit rate. That’s not ideal. For 6-channel audio, we recommend 256 kb/s. 192 is acceptable, but it’s going to be another 20 megabytes to bump it up to 256, so why not do it?
Also, it doesn’t tell you what the source is. So if the original audio was ac3 or e-ac3, it is not going to sound great.