Have been in some discussion w Sean of Zu who has permitted me to release some info
First, the front firing 18" at RMAF prototype likely to be replaced by twin 12" side firing subs, the FRDs likely to roll off at 35Hz to them, and good down to well below 20Hz
There will be built in amplification, but Zu are recommending outboard amps for the subs, at present 20W/ch First Watt B7 seems to be the amp of choice chez Zu. This is because Sean has boosted the efficiency of the subs to that nearly approximating the FRDs, '00s of Watts not needed anymore An outboard low pass filter box will be provided for sub amps using analog filters w greater range of adjustability than current Def 4's
The paper drivers are having some tech at bleeding edge. I'm not at liberty to explain fully, but end result will be massive increase in stiffness w no increase in weight
Lastly, the cabinet will be maxxed for stiffness w ply/resin molded monococque/carbon fibre impregnation multicoring, to max stiffness while remaining light, yet providing a massive anchor to the twin subs
This all suggests to me some thinking from the kind of cabinets used by Vivid Giya and Rockport
All in all, Sean is confident the final released design will maintain the traditional Zu dna of tonal density and verve associated w high efficiency and lack of energy sapping x'overs, with greater dynamic continuity btwn FRDs and higher efficiency subs, greater bass-room integration with the side firing subs, and ability to portray lower level info/micro dynamics with the cabinet rigidity/inertness realised by multicore technology
All in all, a proper set of engineering objectives met to justify the serious price tag of $30k, if Sean's enthusiasm is anything to go by
For my part, the dramatic step up Def 2s to 4s was significant, and Sean claims the Experiences well exceed that margin when going to them from the 4s
I totally trust him on this claim