The VRS Micro surrounds are dipoles, based on Boston Acoustics' THX-certified VRS Pro surrounds. They use a pair of drivers operating out of phase with one another. A co-polymer full-range driver fires toward the front of the room, while a polymer-treated paper mid/high frequency driver (350Hz and up) fires toward the back of the room, creating a "figure eight" pattern to the sides and a null when positioned directly to the sides of the listening position.