Like several other posters have suggested, I suspect there is a setup problem. You mentioned that you are running in phantom mode. That could be the problem. Do you have poor dialogue intelligibility in (unprocessed) stereo? Do you have it from all sources equally, or are some sources worse than others?
If the answer to these last two questions is yes, then the next place I would look is at the room. Bad room acoustics can easily lead to poor dialogue intelligibility.
If the answer to these last two questions is yes, then the next place I would look is at the room. Bad room acoustics can easily lead to poor dialogue intelligibility.