What IS 'fast bass'? Technically, I dunno, but consider this.
133kg each ProAc m/c speakers with ATC 9" bass units (2 in each). Just about as resonance free as you can get for a normal boxed speaker (cue weight !)
Quad 2905s. Same monoblocs (valved); same speaker leads; same everything else.
My aural perception is that the (admittedly reduced range) bass is quicker, and by dint of that, more natural and immediate. Less than milliseconds, possibly, but definitely quicker.
I'm sure there are many reasons for this, but cabinet integrity cannot be one such in my case, i.m.o.
Excuse my technical naivity, but surely moving a charged membrane has to be more efficient than moving a passive speaker cone. Or am I barking up the wrong tree?