SF-2 aside Adriaan as that is such a unique device, as are the F-1X and F-2B. What I am getting at is aside from speakers and power amps that are designed to support the frequency spectrum of a hi-fi bass, cleanly, couldn't a clean warm guitar preamp be a solution for bassists?
This leads back to my question below where the Dual Showman is used, rare exceptions aside, mainly by guitarists.