HF-75High Frequency Component
Introduction
The HF-75 is the high frequency component of the SC-412 and SC-422 two- way, biamplified screen channel loudspeakers for high performance cinema applications. The system is shipped as two separate components: the HF-75 high frequency system and the LF-4115 or LF-4215 woofer system.
The HF-75 high-frequency system features a large format, 3” (75mm) tita- nium diaphragm compression driver mounted on a custom designed high- frequency cinema horn with an adjustable pan and tilt bracket. The horn fea- tures broad horizontal and vertical coverage angles to ensure coverage of every seat in the auditorium. The horn is a low-distortion waveguide provid- ing highly articulate dialogue without the “honky” coloration associated with conventional horn loudspeakers.
The HF-75 includes a driver protection and equalization network. DC block- ing capacitors protect against DC or low-frequency signals that would likely destroy an unprotected driver. Power limiter circuitry protects the driver from over-powering and a response correction filter smoothes the frequency response of the horn/driver combination. The driver and equalization net- work provides for more reliable operation, ensuring the show will go on.
The HF-75 components come pre-assembled to reduce field assembly time. Three bolts are all that are required to secure the HF-75 to the top of the low frequency enclosure.
Mounting
Refer to the illustration for mounting information. The HF-75 attaches to the top of the LF-4115 or LF-4215 with three 5/16-18 bolts, 0.75” long, with lock washers. We recommend the use of serviceable thread locking compound when installing the bolts to prevent loosening due to vibration. Aim the horn in the horizontal plane (pan) before tightening. Adjust the vertical tilt with the bracket adjustment.
Install in accordance with QSC Audio Product’s instructions and a licensed, professional engineer. Only use attachments, mounts, accessories, or brackets specified by QSC Audio Products, Inc. Refer all servicing to qualified personnel. Ser- vicing is required when the apparatus has been damaged in any way.
WARNING! Before placing, installing, rigging, or suspending any speaker product, inspect all hardware, suspension, cab- inets, transducers, brackets and associated equipment for damage. Any missing, corroded, deformed or non-load rated component could significantly reduce the strength of the installation, placement, or array. Any such condition severely reduces the safety of the installation and should be immediately corrected. Use only hardware which is rated for the loading conditions of the installation and any possible short-term unexpected overloading. Never exceed the rating of the hardware or equipment. Consult a licensed, profes- sional engineer when any doubt or questions arise regarding a physical equipment installation.
*TD-000149-00*
TD-000149-00 rev.D © Copyright 2003, 2004 QSC Audio Products, Inc.
QSC® is a registered trademark of QSC Audio Products, Inc. “QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office
