The idea, IMO, of an MBM is mostly about fixing floor and ceiling bounce. By placing a driver on the floor and setting the crossover such that the dominant floor reflection from the speaker is placed in the stop band, you can achieve a very good midbass frequency response (60-120hz or so). This tends to be the hardest response to get right in a room.I'm not familiar with how MBMs are managed in a system that is already running subs and is linear to 25Hz as mine is. With four subs running with HTM-12s, an 88 Special, and six Volt-10LXs, all with bass management at their respective required frequencies, I'm not even sure it's something from which I could benefit. It seems that if the system is already linear through the mid-bass region, the only benefit of running MBMs would be experienced if the main subs were a bit slow in attack of higher amplitude events (percussion in music, and sound effects in movies).
Education required. A primer would be helpful. Is there one somewhere?
It also has additional benefit like increased output, lower XO point to the subs if helpful, takes some load off the mains, etc.