Bookshelf Speakers — Definitive Technology ProMonitor 1000

You have an inch-long tweeter with an aluminum dome membrane and a small phase divider that also protects it from mechanical damage. Below is a 5 1/4" (133 mm) midrange/woofer driver with a polymer diffuser and the proprietary technology of the BDS (Balanced Dual Surround System), according to which the driver membrane is equipped with two suspensions at once - external and internal, and a special phase equalizer is installed in its center.