I glanced at the BK site, didn't see that particularly, altho it is "criitcally damped" for the XLS200DF description I checked, so think that's what they might be referring to, a preference in system Q. More a design parameter/taste thing IMO. I wonder what
@shadyJ thinks about that. The SVS is probably just as "modern" as BK, tho different designs somewhat. Might depend what your "music" is or what your spl or extension goals are.