Low freq. from small drivers? Is it possible

Can you get really low freq. (lets say 30 and down) from a small driver (~6 inch? What is the relationship between driver size and frequency? Most speakers today have went away from a large base driver (10 inches or more). Have we really come that far or is it really a compermize?

Any recomendations for smaller floor standers with good bass?

Thanks,

Dr. Ken