One of the many beautiful aspects of DBA is more subs beats bigger subs every time. The idea of "proper space" for example. If you understand the concept then you know your four subs don't have to be 12" or even 10" they can be 8" or even 6". They don't have to be boxes either they can be tubes. Hsu Research used to make subs that were only about 8" diameter by 30" long and tuned to 20Hz. "Proper space" then is what you already have behind every sofa, under or behind all kinds of furniture, and at the corner of every room.
"Integration" with a DBA comes down to throwing them down, setting xo and level, and enjoy. Really, more people should try it to appreciate just how painless easy and effective it is.