Can't EQ computer speakers

Hi guys, I hooked up my PC to my HDTV via HDMI with the intent of using the TV's optical out port to connect it to my Sony BDV-E390 Home Theater speakers so I can get 5.1 sound out of my computer for my games. It worked, but problem is, the sound card that I'm using (ASUS Xonar DG) came with it's own program for equalization and that worked when I wasn't using the PC with the TV, but now that I am I can't use it at all, any attempt to move the EQ sliders is ineffective and results in no difference in sound at all.

Is there any equalizers out there that could change the sound despite the computer and the Home Theater being connected to the TV? Changing the EQ on the TV itself didn't work and the only equalizing I can do with the home theater involves the horrible factory presets, no custom sliders, which is exactly what I'm looking for. Thanks in advance.