Yes, EQ them darker like with the 560s oratory curve.
The treble lift seems to give bad/average/live recordings the best chance to sound like what the monitor thought he was listening to. Instead of being overstimulated by information about the recording rig, room, or mastering, the dt990 is straightforward with amp stacks and cabinets.
Instead of transducer changes, I firmly believe that modifications to the recorded signal are to be made
via the line-level circuits. This applies to two circumstances: recordings that the listener doesn't like and headphones (or speakers) that the listener doesn't like.
In both cases, use of a different transducer applies a difference to
everything that the listener hears. Whether they like it or not, they can't get away from it. OTOH, line-level EQ can cure the problem when and if the listener desires, and is (with the correct choice of equipment) instantly reversible.
I advise trying EQ first, and see whether one can achieve the desired effect.
Jim