I presume your speakers are on the floor, whether they are floorstanders or stand mounted monitors. I am also assuming the room is carpeted.
You could place the speakers on concrete paving slabs .... this would reduce transmission of bass to the floor and probably help with the low frequency thump, which is likely the main problem. Choose large surface area blocks for stability.
Not very attractive, but cheap, and somewhat effective.
You could place the speakers on concrete paving slabs .... this would reduce transmission of bass to the floor and probably help with the low frequency thump, which is likely the main problem. Choose large surface area blocks for stability.
Not very attractive, but cheap, and somewhat effective.