Do your speakers have spikes? Is your floor laminate?
I have laminate floors and had a major vibration when my sub was setup down firing on spikes. It rattled the floor. I changed it to forward firing on the rubber feet and it went away. Without the spikes down firing configuration resulted in a roaming subwoofer that needed to be tied down.
I have laminate floors and had a major vibration when my sub was setup down firing on spikes. It rattled the floor. I changed it to forward firing on the rubber feet and it went away. Without the spikes down firing configuration resulted in a roaming subwoofer that needed to be tied down.