Take a look at speakers which use multiple ceramic/ceramic composite drivers. Their specs are not as expected for such small drivers. A few years ago I would not have agreed that such diminutive drivers could plumb those frequencies, but it's happening due to technological development. It takes exceptional engineering to have a smaller driver put out lower frequencies. It can be done, but there are trade offs, of course.
It seems the past five years has seen a development technologically of a new breed of drivers (How many ceramic drivers did you see prior to five years ago?) which can do lower frequencies even though more diminutive. The magnets, baskets, coils, etc. everything is changing to achieve that result. I saw very few ceramic drivers several years ago at shows, but now they are becoming quite accepted and for good reason.