I have a couple of cylindrical (sonotube), sealed subwoofers that I made some time ago. At the time, I took the advice of a friend and installed Gold Sound dual voice coil 10" drivers... I have found out (through this forum) that these speakers were never intended for subwoofer use, and my results have always been way below my intentions - I get good bass 'support' but no impact and very little low end. I'm looking for suggestions to replace the drivers with a good, but not too expensive set of subwoofers. Anyone...?