In my own experience, one note bass is mostly a speaker placement issue, but can also be addressed successfully with equalizing down peaks. I know some people are dead set against any kind of equalization, so if that’s out of the question, I think a distributed array of subs to break up the major modes is the only workable solution. Or, a very powerful and extensive array of bass absorbers.
Assuming the bass absorbers are relatively broad band that's what I would have expected as well. Sadly my impression was, room after room, all the speakers bass sounded the same, as if they were playing the same song. 🤣