Or if the cart is too bright to start, maybe something can be done there.
Once you have that you could even attempt to master your own alternate digital versions from there with the right software if you choose rather than banking on it during recording and possibly not getting it the way you want.
Just brainstorming....
On a side note, tonality of Sennheiser headphones in general remind me the most of OHM Walsh tonality, which by all accounts is typically pretty darn flat. I always seem to levitate back to both no matter what over time.