The JBL 3678 cinema loudspeaker system provides natural sound quality for music and dialog in small cinema applications. It can be used in either a passive mode, using its built-in network, or in a bi-amplified system.  Enclosure design is extremely shallow in depth (292 mm; 11.5 inches), to minimize the space required behind the screen.

The high-frequency section consists of the JBL 2426 pure titanium compression driver and 2342 Bi-Radial horn. The titanium diaphragm of the 2426 ensures the natural sound and reliability mandatory in today’s motion picture theatres. The 2342 horn provides smooth, even coverage throughout the auditorium.

The low frequency section uses a single JBL 2226H driver. This 600 watt driver features JBL-patented Symmetrical Field Geometry (SFG) and Vented Gap CoolingTM technology for high power handling with minimal power compression.

The newly-designed passive crossover network is optimized to provide seamless transition between driver components, for clear, articulate dialog, and high fidelity music reproduction. Operation in a bi-amplified system is easily achieved by simple re-configuration of the jumper connectors at the network/connector panel.

In bi-amplified mode, the 3678 is THX-approved for THX certified theatres no larger than 1,274 cubic meters (45,000 cubic feet) and screen-to-last row distances no greater than 12.2 m (40 ft.).