All I know is I've heard extremely satisfying "low" bass,from the Mini.This in a room about 21 x12.5x8.
No,I did not actually measure exactly how low it was....
Why?....because I was totally satisfied with the numerous reference discs we played,and if the bass was sufficient on these superb discs,I/we were totally happy.
I know how much low frequency material is on these discs,and have heard them on many set-ups(some with multiple driver/woofers,also very well set up).The Mini "Maxxed" them out.
Maybe not good enough for the technically oriented crowd,but very convincing to me.All anyone should really be concerned with is if the music "sounds" convincing.
In the right room,it certainly does.One reason,I suspect,it's so popular....If the room is a cavernous one,obviously common sense dictates one use a different speaker.
The Mini goes low enough to say..."who cares"?It's that good,when well driven,in a room of appropriate volume(which is common).
Best