NX-Otica/-Treme have the wing at the MTM section....why not x-Statik?
Because the X-Static has a sealed set of mid woofers to handle bass... extending into the 40s or 50's. The others are designed to hand off to subs reaching up to just below 200Hz. The wing is for bass augmentation to get it to reach down when open baffle.
If I understand it correctly....