I want to say a big thank you to
@csglinux who helped me a lot chosing a matching DAP for the ShureSE846.
As
@csglinux mentioned its difficut to find a DAP which meets all the requirments of a high quality source that are capable of driving the SE846 without more or less drawbacks.
In the SPL diagrams of the DX200 you can clearly see the sub-bass roll off which
@csglinux mentioned and as the SE846 have a dedicated sub bass driver that is capable of providing such low frequencies you don't want to have a DAP which is not able to provide this low frequencies and is limited here.
It is true that only from measurements, you can't say that an DAP (or amp) sounds really good.
The other way around however is true, that you can identify disadvantages with the measurements.
Long story short, a good matching DAP (+amp) is always essential and should be well considered, especially for difficult to drive properly IEMs like the SE846.
And measurements and helpful user descriptions here definitiv helps a lot (at least for me),
even when the last decision should be made in person with a physial listening experience.
Thanks for your support!