Modding the crossover for REL Tzero mk3 subwoofer?

Hello! I wonder if I am the only one who seems to be annoyed that the REL Tzero mk3 seems to have too much mid bass that bleeds into vocal ranges… I find the crossover on the back sloping too gentle and would want to modify it to have a more aggressive/sharp cut off slope.

I’m paring it with the Ls3/5a which has a huge 100hz mid bass bump to compensate the lack of bass, hence the leak from the sub is extremely noticeable…