5.1 setup.
It seems gun shots and explosions come from all speakers equally making it impossible to pinpoint a direction, while vehicle sound like tanks and helicopters have proper surround and play from the right direction.
Eg someone shooting direcly behind me = sound played from front (all?) speakers.

Going into distance gunshots seem to get better directional placement.
In Arma2 sound (direction) was working perfectly and also occulsion was working better.