Designed and engineered in JBLs world-famous acoustic engineering facility in Northridge California the 4309 Studio Monitor is a showcase of patented JBL acoustics technologies. This bookshelf loudspeaker features a 2-way design with patented High-Definition Imaging (HDI™) horn technology the patented 2410H-2 1-inch (25mm) compression driver and a 6.5-inch (165mm) cast-frame Pure-pulp cone woofer for powerful dynamics and incredibly accurate sound reproduction. JBLs revolutionary High-Definition Imaging horn geometry is the result of intense research into the nuances of horn design. In search of exceptional high-frequency detail and uniform directivity for smooth in-room response JBL engineers pioneered a design that delivers neutral frequency response both on- and off-axis and provides a seamless transition between the high and low frequency drivers. The JBL 2410H-2 compression driver benefits from the advanced research and applications derived from JBL Professionals \"D2\" range of transducers. At the core of the 2410H-2 device is a lightweight polymer annular diaphragm that improve high-frequency extension by reducing diaphragm mass. The V-shaped geometry of the annular diaphragm reduces breakup modes eliminating time smear and reducing distortion. The result is incredible dynamics with accurate reproduction and a lack of power compression.