Active Monitor with 6.7" LF Driver, 1" Dome Tweeter, Acoustic Space Control, LF Roll-off, HF Shelf (each). The Mackie HR624mk2 active studio monitors manage to improve on the widely-used originals. New features, such as a solid aluminum Zero Edge baffle and optimized waveguide help to give the HR624mk2 even more accurate, natural sound reproduction. Designed with high-definition audio in mind, this monitor provides exeptional clarity for surround 5.1 and 7.1 applications, and an Acoustic Space Control function allows it to be adapted to any room and still provide maximum accuracy. Low-frequency roll-off and high-frequency shelf functions are also included on the HR624mk2.