Sounds will bounce off flat solid surfaces, in a empty room this will be compounded as the echos will bounce off again and muliply, like a sh1t reverb and delay combined....
You probably could do with something to absorb some of the reflections, carpets, curtains, sofa's all work well....
Speaker placement and careful set up of eq etc will also help.

You need to get some acoustic treatments for your walls and also make sure you are not getting standing waves, desk splash, unwanted reflections,etc. There is a program called acousticX which will do an analysis of your room (you can enter dimensions, materials etc) and give you the best speaker placement. Make sure you are also using spikes either under the stands or the speakers or both.
Wood floors are also a bitch for reflections so lay some thick rugs down and if the walls are reflecting badly, hang some fabric that has texture and is not flat (i.e. hang it like so it looks like corrugated iron).
Without trying to hurt your feelings, EQ'ing and spending loads on acoustic treatments is a little wasted on those speakers.