*TD-000150-00*
Cinema Loudspeaker Systems User Manual
SB-5118 and SB-7118
SINGLE-18” Subwoofers
Introduction
The SB-5118 and SB-7118 are specially designed cinema subwoofers, featuring 500 and 700
watt, respectively, 18” (460mm) low-frequency transducers mounted in ported enclosures. The
enclosures are tuned to 25 hertz and use a B6 alignment. These should be used with the B6
boost filter option provided by the QSC SF-1 or SF-3 Subwoofer Filter modules or the QSC Dig-
ital Cinema Monitor to ensure extended response to the lowest audible frequencies.
Meeting cinema requirements for the extended low frequency response differentiates the SB-
5118 and SB-7118 from more conventional “rock-and-roll” subwoofer systems. Their fre-
quency range extends to below 25 hertz when used with the correct B6 filter.
The two custom 500 watt (700 watt, SB-7118), 18” transducers were developed especially for
cinema use. The woofers feature 4” (100mm) voice coils and vented pole pieces to ensure cool
operation, even at high power levels. Cooler temperatures increase driver lifespan and
decrease problematic power compression at high drive levels. Undercut pole pieces provides a
Symmetrical Magnetic Gap (SMG), reducing second harmonic distortion.
Enclosures are constructed of high quality MDF panels.
Large, Fully Radiused Ports (FRP) ensure smooth air flow through the ports, especially at higher
drive levels. This prevents potentially audible port turbulence noise. Both internal and external
port openings are fully radiused.
With Symmetrical Port Loading (SPL) bass ports are evenly spaced on each side of the trans-
ducers, making internal pressure more uniform across the back surface of the transducer. This
prevents the cone from being displaced to one side or another by unbalanced air pressure,
reducing the chance of driving the voice coil out of the center of the gap at high drive levels.
Enclosure is not designed to be suspended, flown, or rigged. Do not suspend,
fly, or rig this enclosure.
This product is capable of producing sound pressure levels that can perma-
nently damage human hearing. Always keep sound pressure levels in the lis-
tening area below levels that can damage human hearing.
Install in accordance with QSC Audio Product’s instructions and a licensed,
professional engineer. Only use attachments, mounts, accessories, or brack-
ets specified by QSC Audio Products, Inc. Refer all servicing to qualified per-
sonnel. 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 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, professional engineer when any
doubt or questions arise regarding a physical equipment installation.
TD-000269-00 rev.A
© Copyright 2007, 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
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
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