I'll chime in as well that it is most likely what the other gents are saying. A few strategic acoustical treatments could really do wonders for the "black hole." Try moving things around a bit like mentioned since that just costs some time, but be ready to look at some bass traps. They don't have to be huge monsters in order to provide benefit, it is just making sure that they are big enough to make a noticeable benefit.

Farewell - June 4, 2020