How can I setup gstreamer (rhythmbox) to work with specific .sf2 sound bank (using fluidsynth, for example?) Thank you.
Here are instructions to make sf2 files available to wildmidi (and thus gstreamer): https://cybolic.wordpress.com/2011/04/26/gstreamer-midi-and-ubuntu/
Worked beautifully for me (although unsf may crash for your sound bank, didn't seem too robust).
Should work ok in rhythmbox, assuming that it uses wildmidi plugin. From the command line: