Tricky and interesting question. I'd say 25Hz at -0dB at least. And why is because when I added subs and EQ'd it carefully it plays near flat 200 down to 25Hz now (no lumps). I hear things in recordings I never heard before, and that is always great.
Because of DBA I will always say more subwoofers are better (all turned down low). But I believe that in terms of frequency reproduction and deep low bass, there are flagship products, Wilson, Magico, et al, that I would consider full range (knowing add'l subs would aid low end quality).
Because of DBA I will always say more subwoofers are better (all turned down low). But I believe that in terms of frequency reproduction and deep low bass, there are flagship products, Wilson, Magico, et al, that I would consider full range (knowing add'l subs would aid low end quality).