I think the 2001 Sovereign I heard at CES eons ago were regular/not signature (actually didn't know they made a signature). It is one of my favorites ever, even near field in a small room as when I auditioned them. Kinda weird hearing the performance then seeing these beasts a few feet away. Sure are big & heavy. Are you thinking of buying a pair? I don't know how they could be shipped safely w/ insurance et all. Best wishes on your search.