Right now the Tracers module (the one that simulates Anti Air Artillery) has a really boring sound.
It feels like someone just took a random light machinegun and started shooting in the air.
It should have a more menacing and powerful sound, like a BIG gun shooting, or maybe use the proper Tigris/Cheetah sound for when it fires.
There are some good examples on youtube of what a SPAAG sounds like.