The 3678-HF screen channel system can be used in either the passive mode or in a bi-amplified system. THX®-approved for THX system applications. It features high frequency transducer: 25 mm (1 in) horn throat diameter, 44 mm (1.75 in) pure titanium diaphragm compression driver. Flat power response 100° x 100° Bi-Radial® horn. Operable in bi-amp or passive mode. Includes adjustable bracket for horn aiming. Shallow profile cabinet minimizes behind-screen space requirements. THX® - approved for THX system installations (biamplified only).