Bad generalization. I know a lot of speakers that go down seriously low, right into the double digit frequency range. Some floorstanders have dedicated bass drivers. Though obviously quantity will not be as much as the floor-facing drivers of dedicated subs (PC ones tend to be bollocks, by the way, the only difference between them and normal satellites being the cone size and a crossover circuit so they only play the low frequency), but they certainly can sound good, and they definitely aren't in the 'no bass' range. If you buy a set of good bookshelves or PC satellites that aren't meant to be used with a sub, and they have no bass, then they just plain suck.