Thinking with the amp software you’d want to esys flash the B&O amp it with the smallest cabin option of the supported BMW models to get the DSPs time alignment and cabin gain adjustments closer to the dimensions of the F3x chassis.
EG , compare 5 series to others from a dimensional point of view and speaker placement. Ideally you wouldn’t want to run x5-x6 or 7 series software with their larger cabins.
Otherwise, it could be a case of tailoring your equaliser settings. There is a thread on bimmerpost Ecco system that had a sound engineer coming up with a shallow V shape across the EQ range. That might be to your liking.
Key for flashing would be to work out which amp software applies to which BMW model. Guessing some of the coders on here would be able to work that out.
https://www.carsized.com/en/cars/com...x5-2015-suv-m/
https://www.carsized.com/en/cars/com...-5-2010-sedan/