I had the SB12-NSD,and Older Cylinder Sub[cant remember the Model Number]
sold both to friends-they are still working Great,and now use 2 PC2000 Cylinder Subs
no complaints,great service and good Value.I have not had many other good Brands,except HSU=also good;so the only Negative is the lack of Speaker Level Inputs.Buy at least a pair of whatever Brand you end up with.