Fulcrum Acoustics US221-2 Dual 21" Subs (Pair) - $4,800

The US221-2 is a dual 21 inch, ultra-compact, direct radiating subwoofer.
Its 6 inch voice coils, unusually rigid cones, and innovative low-turbulence ports permit an optimal tuning to be achieved in an enclosure that is smaller than most dual 18 inch subwoofers.
These subs are in good used condition.
They are the installation version and come with four large, rubber isolation feet on each speaker.
I have tested each driver individually, and I've included a screen shot of the frequency response of each sub.
The price is $4,800 OBO for the pair.
Full specs can be found here: https://www.
fulcrum-acoustic.
com/product/us221-2-dual-21-direct-radiating-subwoofer/