Two Full Size Marty Subwoofers, 18" Drivers, Duratex Finish, Great Drivers purchased in 2020 and gently used in a small 1500 CU Ft theater room. The boxes are well braced and made with birch plywood, not MDF. Please see pictures on Seattle Craigslist.
Awesome driver, One with B&C 18DS115-4 18" Neodymium 4 Ohm Driver, Quick WinISD shows...
114db @ 18 Hrz117db @ 40 Hrz120db @ 60 Hrz122db @ 80 Hrz126db @ 200 Hrz
Look at those extra db at the bottom end, like having the output of 2 Marty subs! Perhaps the second best 18" Driver for the (B&C IPAL #1)??