Honestly, I have to question subs playing that loud. I found that when they were set more than very low in my audio system, they collapse the soundstage and screw up the midrange and treble. They should not be heard.
I used to have 4 800 series subs, two in our HT and two in my audio system. When properly adjusted one could barely feel vibration from them with heavy bass. In my home theater playing the depth charge scenes from U-571 shook our whole house and they would vibrate a little with one’s hand on top.
From what you say, there is something very wrong.