Bingo!
You might also consider moving sub to a less excitable location in the space.
subwoofer buzz - how to eliminate it
MartinLogan Dynamo 700w
At low frequencies, it vibrates, like it wants to fall apart. It does have a rubber feet, sitting on a hardwood floor, what could prevent it? Isolation feet? More rubber? Also it's facing the floor but can be turned sideways, would that help?