Has anyone checked to see what sound API the game uses? If it uses one which supports DirectSound, then either a translation wrapper (like Creative Alchemy) might be able to rectify the surround sound issue. At the same time, though, I realize it's more likely the game uses something like FMOD or a custom cross-platform solution.
Topic on Talk:Final Fantasy XIII-2
It's not like FMOD couldn't then use in turn either XAudio2, DirectSound or OpenAL
EDIT: ok, it cannot since version 4.33dev4 (~2010). Then I guess development inertia can do "miracles" at times, but I think 4 years should be enough for anybody to update its middlewares.
True, but in my experience and from what I've read, modern cross-platform games (as in games which can be played on consoles and Windows, but not Mac OSX and Linux) which use audio middleware tend to use XAudio2, and thus do not attempt to accelerate their audio processing through capable hardware.
XIII-2 claims to use the Miles Sound System middleware (http://www.radgametools.com/miles.htm), which itself has an option to wrap DirectSound.