Analysis Audio Planar Ribbon speakers use a first order crossover at 600 Hz.
Arion Audio Apollo speakers use fourth order filters at 120 Hz.
If the drivers and system are designed for it and the drivers have the headroom it can work very well. There are very many things that have to be taken into account. For example our Arion AMT drivers are mechanically damped so they are able to follow complex wave forms which is exacerbated by the extended range they must reproduce.
I have enjoyed DD67000s on many occasions. A wonderful speaker by many accounts. I'm sure the engineers at JBL did their homework and met their design objectives.