These guys convert the electrical signal back into sound waves by vibrating their “drivers" back and forth to reproduce sound frequencies in the air.
Bigger cabinets generally mean that the speakers reproduce lower bass notes more effectively. But of course, it’s popular now to keep everything small. The subwoofer is probably the latest real innovation in speaker technology that has allowed this trend of smaller speakers to thrive without compromising too much on sound quality.
However, all things being equal, it is generally true to say that in speaker world, “bigger IS better!”