No it is not an active crossover, but an active equalizer, which are required for all Qb6 alignments.
We should visit the coupled cavity bass systems once more. They are compact and efficient, and their major attraction is being able to control Q. The KUBE for these speakers gave the, owner wide selection of Q, over the bass system.
Those speakers I built as monitors, I used in Eagan, I did design and build an active crossover, variable Q system for. However, when I moved to Eagan I drove that bass system from Sub outs of the pre/pro. I had designed the native Q at 0.7 which was fine.
These coupled cavity systems have fallen out of favor with the developments of HT. The problem is that bandwidth is limited. Also bandwidth is dependent on Q. The lower the Q is the lower the bandwidth. So at Q 0.5, bandwidth is very limited, but bass quality is good. As you widen the bandwidth of the design, Q gets very high and bass quality falls off the cliff.
So the issue for HT becomes the LFE signal that does not roll off until 120 Hz. If you design a coupled cavity sub with a bandwidth of 20 Hz to 120 Hz, it would have a high Q, and a sloppy oozy bass, ala Bose.
So they work best as a passive crossover. Since roll off is 24 db per octave at both ends, then you can make a nice acoustic crossover for a ported speakers. Say you have a speaker, Qb4 ported box with an F3 of 50 Hz, then you can design a coupled cavity sub with a bandwidth of 20 Hz to 50 Hz, and low Q and get a perfect acoustic splice at crossover. However it will not handle the LFE channel. I have done designs like that, and I'm using one now in our family room. However I have an elegant WAF friendly solution up my sleeve, to change that in the near future.