Mac Mini (Late 2012) HDMI Audio Control

So something I've only recently noticed and I was wondering if there is a workaround since it is ever so slightly annoying.

On my Mac mini (Late 2012) model, I have it plugged into a HDMI monitor that has integrated speakers via a standard HDMI cable...

I can hear audio just find however nothing on the Mac mini itself is able to control the volume level of the output from those speakers like it can on normal speakers. Am I just missing a setting or is this normal expected behavior with the audio over HDMI. I normally use Display Port connections so this is my first time playing with a Mac mini and HDMI...

All the options for volume control are greyed out, screenshots below.

Included for Reference...