Interesting speakers. However the trouble of putting a serial number on them looks as easy as printing a Label on a computer and sticking it on the cabinet. Doesn’t make sense, but if they sound good, who cares.Ha ha ha......he told me bluntly they looked like crap. He does not know if they are Advance or not......"maybe they are or maybe they are not". He didn't seem too interested. He told me that he doubts they are a DIY or knockoff. He doesn't think anyone would go to the trouble of putting serial numbers on them. So, the mystery remains. Thanks for your interest and asking.
Best of luck with them.