The VTF-3 has an advantage in that it can be set-up either for maximum output (with a 25 Hz tune), or Maximum Extension with an 18Hz tune. In Max Extension, the '3 measured down 3 db at a very deep 16Hz, and this was done outdoors. In max extension mode, the '3 will have nearly a 10 db advantage in the deepest bass. Not even close.
This is not to slight the SB-12, it is simply not possible to achieve the same deep bass response from a tiny sealed box as you can get from a box 3X the size and ported, rather than sealed.
This is not to slight the SB-12, it is simply not possible to achieve the same deep bass response from a tiny sealed box as you can get from a box 3X the size and ported, rather than sealed.