Digital filters are awesome because of their flexibility.
In the case of loudspeakers - and particularly controlled directivity loudspeakers - you have to be careful with your choice of filters because they affect summing through the crossover region. So steep slope filters aren't necessarily your best bet. Nor are first-order filters necessarily your best bet.
In my experience, the best filter is found using a process like I describe in the link below:
And for room modes, no electrical filter is sufficient because the most sophisticated filter can only have a two-dimensional effect, whereas room modes are a three-dimensional phenomenon. The solution for room modes is flanking subs and multisubs.