Display / Screen resolution on PC ( X86 / X64) Systems

I use the Volumio PC ( X86 / X64 ) system with HDMI Output.
It seems Volumio uses always the maximum resolution and i cannot find anything to change this.
When i use Volumio in my living room with a 4K Display the text is very small and i would like to change the Display resolution to be able to read and operate volumio from a larger distance.