I have an ASUS VS228 connected to a Mac Mini with HDMI. In sound prefs, I can choose the monitor (HDMI) as the output, but then all the options are greyed out. Changing the volume setting has no effect. I searched and there are no asus drivers available. Also i have been through the settings on the monitor, and only find a volume level 1-100. I have it set at 100. Anyone know if this is the monitor, or the computer, or any other input? I'd appreciate it!!!