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30” (762 mm)
20” (508 mm)
16”
(406 mm)
*TD-000326-00*
Cinema Loudspeaker Systems User Manual
HF-75B
High Frequency Component
Introduction
The HF-75B is the high frequency component of the SC-312B, SC-412B,
SC-322B, and SC-422B two-way, biamplified screen channel loudspeakers for
high performance cinema applications. The system is shipped as two separate
components: the HF-75B high frequency system and one of the woofer systems
(LF-3115, LF-3215, LF-4115 and LF-4215).
The HF-75B high-frequency system features a large format, 3” (75mm) titanium
diaphragm compression driver mounted on a custom designed high-frequency
cinema horn with an adjustable pan and tilt bracket. The horn features broad hori-
zontal and vertical coverage angles to ensure coverage of every seat in the audi-
torium. The horn is a low-distortion waveguide providing highly articulate dialogue
without the “honky” coloration associated with conventional horn loudspeakers.
The HF-75B includes a driver protection and equalization network. DC blocking
capacitors protect against DC or low-frequency signals that would likely destroy
an unprotected driver. Power limiter circuitry protects the driver from over-power-
ing and a response correction filter smoothes the frequency response of the horn/
driver combination. The driver and equalization network provides for more reliable
operation, ensuring the show will go on.
The HF-75B components come pre-assembled to reduce field assembly time.
Three bolts are all that are required to secure the HF-75B to the top of the low fre-
quency enclosure.
Mounting
Refer to the illustration for mounting information. The HF-75B attaches to the top
of a woofer system with three M8 bolts, 20mm long, with lock washers. We recom-
mend 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, LLC
Refer all servicing to qualified personnel. Servicing 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, cabinets,
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 instal-
lation 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 rat-
ing of the hardware or equipment. Consult a licensed, professional
engineer when any doubt or questions arise regarding a physical
equipment installation.
TD-000326-00-B
© Copyright 2010 QSC Audio Products, LLC
QSC® is a registered trademark of QSC Audio Products, LLC
“QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office
1675 MacArthur Blvd., Costa Mesa, CA, 92626 USA
Main Number (714) 754-6175 Sales & Marketing (714) 957-7100 or toll free (USA only) (800) 854-4079
Customer Service(714) 957-7150 or toll free (USA only) (800) 772-2834
