Can't control bass volume

[LucasG]

I am currently using my GA-P35-DS3R motherboard integrated soundcard which is Azalia audio and have installed the latest drivers from Realtek.com and I have a Logitech Z-530 5.1 set. I am having the issue that I cannot control the bass volume or anything of that. If I go to the sound volumes and turn the subwoofer to 0 nothing happens. It's been like this for a while, drivers are the latest... but I can't make it work at all.

Help is appreciated.