Comment by mrob

It's not fair comparing speakers to headphones/earphones, because speakers have to move a lot more air. Cheap earphones can have excellent bass response because they're coupled directly to the eardrums. The NS10s only have 18cm (7in) woofers, so it's not surprising their -3db bass cutoff is 70Hz. As "Hoffman's Iron Law" of loudspeaker design says: deep bass, small size, high efficiency: choose two.