Terrible Booms

Stani19, Describe the construction of your floor for me. You mentioned Parquet with voids below? Is it Parquet on a wooden joist floor? What is the width of the joists 10"? What are the dimensions of the room. Is there a basement under the floor and is it finished or unfinished? It sounds to me you were on top of the problem to begin with. I was involved in two situations were the floor was the problem. In both cases the joists were too small for the span they covered and the floors bounced. We fixed it by putting beams across supported by lolly columns below.  One floor was actually sagging over an inch in the middle.

stani, I think the recommendation for a high quality small monitors on stands is perfect for you just add two 10" sub woofers. The Rogers LS/35A is perfect. Cross to the subs at 125 Hz and put the subs right in the corners with the monitors 3 feet from the rear and side walls. Put absorption panels on the side walls at the primary reflection point.
Personally, I have never liked bass reflex speakers.