It is rare for a speaker to get down to 20 Hz unless it is enormous in size. I used to have seven feet tall and 15" in diameter subwoofers with 2000 watts on them. They got down to 17 Hz. I never could integrate them with anything. I also only had Hartley 24" subwoofers first mounted a ceramic sewer tiles and later in big boxes. They couldn't do much over about 24 Hz. I think I had 700 watts on each.
Nope, Norm
Nope, Norm