The only way you're going to 'edit' the default flac or any other encoder settings in RB or sound-juicer is thru the use of a gstreamer preset. It would also appear that you can only make use of one preset per encoder type at a time. (you can create multiple presets per encoder but only one will be able to be used.
Discussed here, atm there is nothing in place but very easy to set up as a user, support if needed via the link in my last comment Bug 945987 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/879525 Title: Rhythmbox CD ripping to FLAC broken To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/rhythmbox/+bug/879525/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs