@sudnh , Many times, the 1 note boom is because you're seated right on top of a room modal peak. Other times, the perception of a 1ish note boom can come from ported subs and associated group delays. The big SVS ported subs have appeal for the boominaughty hometheater dudes when they're watching Godzilla or some fratty maverick shooting things (SVS's primary market). A SVS sealed sub integrated correctly won't give you 1 note boom.
P..S. That neck bearded reviewer on the vid though...he kinda looks/ sounds like a 1 note boom,