i works just like a port......the actual sub moves in that thing will push out , sub moves out that thing will suck in ...............moves air just like a port would
how strange, is it for small boxes where theres not enough room for a ported box? how much does it increase the sound? sure would like to see one in action in person
They're not like a port in a box per-say...they're more of an inactive subwoofer that resonates as the active sub resonates theoretically creating more sound output than a single sub would produce without taking up the space that 2 subs would.