Yeah, I think the BMRs are great, especially if you are on a budget since you can easily cross them over with a gentle slope if choosing a typical crossover point. My personal favourites are the TEBM46C20-4 at the moment, they seem to have the best off-axis performance. Apparently they’re coming out with BMR-k line of drivers at some point though, which are their next gen BMRs which should be fun. If going passive, the best sound quality would be to have plenty of crossover between the two drivers’ frequency range, that way you can do 1st order crossovers which have very minimal phasing issues so off-axis response, vertically, (and therefore power response too) will be much more behaved too, plus a smoother transition between directivities of the two drivers. Honestly, IMO, one of the best builds you can probably do on a tight budget.