There is a known bug with SoundConverter and newer versions of GStreamer which has a fix in git. The tricky work with
sed below duplicates the upstream patch which is not yet present in the Ubuntu package:
Copy and paste the entire code below into a Terminal window:
sudo sed -i_bak 's/opusenc bitrate=%s cbr=false/opusenc bitrate=%s bitrate-type=vbr/' \
2. Reverse the fix:
If you would like to reverse this simple hack run the following single command:
sudo mv -v /usr/share/soundconverter/python/soundconverter/gstreamer.py_bak \
And SoundConverter will be returned to its original state :).