Sounds like you need to spend some time figuring out what's wrong with your system, room, or the sub itself, cause in my four years of owning SVS subs, I can assure you there is nothing "awful" about them. I also have yet to hear "muddy and boomy". In fact, I hear the exact opposite of that.
Our 16-46 octet and twin B-4/12 woofing babies set up produces 25 megatons going full board (eat it, Iran!)...all the while doing it mucho MUSICALLY too!...
-THTS
"...hi, my name is Frank...and am an SVS bassaholic!..."