Very common problem. You have two choices, acoustic treatment of the room or a room control preamp like the Thrinnv Amethyst or DEQX Pre 4. Ideally you would do both. First you need absorption panels at the major first reflection points. You find them with a mirror since sound and light bounce the same way. Sit in your listening position and have a helper hold a mirror at your eye level. Have them move the mirror across the front wall from behind the left speaker to the right. When you see the speaker in the mirror put a masking tape marker on the wall behind the mirror. Now continue moving towards the right and when you see the right channel speaker in the mirror mark the wall there. Now do the same maneuver on both side walls. These are the four main first reflection points and you need to put sound absorption panels at these locations. There are also first reflection points on the floor and ceiling which may need to be treated. This will get rid of some or even all of that "shoutiness" which we call sibilance, the bane of residential HiFi systems. If this does not calm it a room control preamp will. They will also give you a programmable subwoofer crossover should you ever feel the need for more slam.