Man you’re coming across dense. Behind that woofer and in that little box is what are commonly called the motor structure and amplifier. When you ask for smaller where do you expect those two things to go and still have safe enclosure size and physical space for an amp that will stay in working temperature?
I think you’re just being lazy and don’t want to put the work in to find a unit with a Physically smaller footprint. Look at the dimensions of the Audison, google active subwoofers, and check the specs of whatever pops up. Need a tip, if the Audison is too big and it’s a 10, start with looking for an 8.