I've read few past threads on this same subject, but now I think it's time for some new updated opinions.

Me personally, I feel like my Adam A7x's sound good and revealing for playback, but I really can't achieve a good mix on them. I normally have to go back and change things, could it be because I don't have a sub? When I'm at my cousin's studio, I get a better mix on his Dynaudio BM5a mk2's. I'm starting to think I should make that switch myself, or maybe add a sub to my monitor system? I say add a sub because its normally low end issues. None of our music rooms are treated. Could that mean that the Dynaudio's are better than the A7x?