I am assumming you are using pulseaudio. If not then just ignore my post.
I have F10 and F12, so not really sure which one of the following applicable to F11.
In F10, I modified /etc/pulse/daemon.conf to have below entry:
default-sample-channels = 8
The number is of course depends on the number of speakers you have. I got this tip from one of the post from this forum.
In F12, the surround speakers support is just a matter of selecting the right option in the gnome-volume-control.